Linear Models

Srishti Puri

4/1/2021

Question: Create a linear model and interpret the results. Use the Marketing.xlsx data. Requirements

Result of the model:

Explore data:

##     MarketID       MarketSize          LocationID      AgeOfStore    
##  Min.   : 1.000   Length:548         Min.   :  1.0   Min.   : 1.000  
##  1st Qu.: 3.000   Class :character   1st Qu.:216.0   1st Qu.: 4.000  
##  Median : 6.000   Mode  :character   Median :504.0   Median : 7.000  
##  Mean   : 5.715                      Mean   :479.7   Mean   : 8.504  
##  3rd Qu.: 8.000                      3rd Qu.:708.0   3rd Qu.:12.000  
##  Max.   :10.000                      Max.   :920.0   Max.   :28.000  
##    Promotion          Week      SalesInThousands
##  Min.   :1.000   Min.   :1.00   Min.   :17.34   
##  1st Qu.:1.000   1st Qu.:1.75   1st Qu.:42.55   
##  Median :2.000   Median :2.50   Median :50.20   
##  Mean   :2.029   Mean   :2.50   Mean   :53.47   
##  3rd Qu.:3.000   3rd Qu.:3.25   3rd Qu.:60.48   
##  Max.   :3.000   Max.   :4.00   Max.   :99.65

##      var frequency percentage cumulative_perc
## 1 Medium       320      58.39           58.39
## 2  Large       168      30.66           89.05
## 3  Small        60      10.95          100.00

Performing Initial data preparations:

raw0 <- Marketing %>% 
  select(-LocationID) %>% 
  mutate(MarketID = as.factor(MarketID) ,
         Promotion = as.factor(Promotion) ,
         random = runif(548))

summary(raw0)
##     MarketID    MarketSize          AgeOfStore     Promotion      Week     
##  3      : 88   Length:548         Min.   : 1.000   1:172     Min.   :1.00  
##  10     : 80   Class :character   1st Qu.: 4.000   2:188     1st Qu.:1.75  
##  5      : 60   Mode  :character   Median : 7.000   3:188     Median :2.50  
##  6      : 60                      Mean   : 8.504             Mean   :2.50  
##  7      : 60                      3rd Qu.:12.000             3rd Qu.:3.25  
##  1      : 52                      Max.   :28.000             Max.   :4.00  
##  (Other):148                                                               
##  SalesInThousands     random        
##  Min.   :17.34    Min.   :0.001137  
##  1st Qu.:42.55    1st Qu.:0.290522  
##  Median :50.20    Median :0.540287  
##  Mean   :53.47    Mean   :0.528167  
##  3rd Qu.:60.48    3rd Qu.:0.784319  
##  Max.   :99.65    Max.   :0.996996  
## 
CrossTable(raw0$MarketID , raw0$MarketSize)
## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## | Chi-square contribution |
## |           N / Row Total |
## |           N / Col Total |
## |         N / Table Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  548 
## 
##  
##               | raw0$MarketSize 
## raw0$MarketID |     Large |    Medium |     Small | Row Total | 
## --------------|-----------|-----------|-----------|-----------|
##             1 |         0 |        52 |         0 |        52 | 
##               |    15.942 |    15.415 |     5.693 |           | 
##               |     0.000 |     1.000 |     0.000 |     0.095 | 
##               |     0.000 |     0.163 |     0.000 |           | 
##               |     0.000 |     0.095 |     0.000 |           | 
## --------------|-----------|-----------|-----------|-----------|
##             2 |         0 |         0 |        24 |        24 | 
##               |     7.358 |    14.015 |   173.828 |           | 
##               |     0.000 |     0.000 |     1.000 |     0.044 | 
##               |     0.000 |     0.000 |     0.400 |           | 
##               |     0.000 |     0.000 |     0.044 |           | 
## --------------|-----------|-----------|-----------|-----------|
##             3 |        88 |         0 |         0 |        88 | 
##               |   138.026 |    51.387 |     9.635 |           | 
##               |     1.000 |     0.000 |     0.000 |     0.161 | 
##               |     0.524 |     0.000 |     0.000 |           | 
##               |     0.161 |     0.000 |     0.000 |           | 
## --------------|-----------|-----------|-----------|-----------|
##             4 |         0 |         0 |        36 |        36 | 
##               |    11.036 |    21.022 |   260.742 |           | 
##               |     0.000 |     0.000 |     1.000 |     0.066 | 
##               |     0.000 |     0.000 |     0.600 |           | 
##               |     0.000 |     0.000 |     0.066 |           | 
## --------------|-----------|-----------|-----------|-----------|
##             5 |         0 |        60 |         0 |        60 | 
##               |    18.394 |    17.786 |     6.569 |           | 
##               |     0.000 |     1.000 |     0.000 |     0.109 | 
##               |     0.000 |     0.188 |     0.000 |           | 
##               |     0.000 |     0.109 |     0.000 |           | 
## --------------|-----------|-----------|-----------|-----------|
##             6 |         0 |        60 |         0 |        60 | 
##               |    18.394 |    17.786 |     6.569 |           | 
##               |     0.000 |     1.000 |     0.000 |     0.109 | 
##               |     0.000 |     0.188 |     0.000 |           | 
##               |     0.000 |     0.109 |     0.000 |           | 
## --------------|-----------|-----------|-----------|-----------|
##             7 |         0 |        60 |         0 |        60 | 
##               |    18.394 |    17.786 |     6.569 |           | 
##               |     0.000 |     1.000 |     0.000 |     0.109 | 
##               |     0.000 |     0.188 |     0.000 |           | 
##               |     0.000 |     0.109 |     0.000 |           | 
## --------------|-----------|-----------|-----------|-----------|
##             8 |         0 |        48 |         0 |        48 | 
##               |    14.715 |    14.229 |     5.255 |           | 
##               |     0.000 |     1.000 |     0.000 |     0.088 | 
##               |     0.000 |     0.150 |     0.000 |           | 
##               |     0.000 |     0.088 |     0.000 |           | 
## --------------|-----------|-----------|-----------|-----------|
##             9 |         0 |        40 |         0 |        40 | 
##               |    12.263 |    11.858 |     4.380 |           | 
##               |     0.000 |     1.000 |     0.000 |     0.073 | 
##               |     0.000 |     0.125 |     0.000 |           | 
##               |     0.000 |     0.073 |     0.000 |           | 
## --------------|-----------|-----------|-----------|-----------|
##            10 |        80 |         0 |         0 |        80 | 
##               |   125.478 |    46.715 |     8.759 |           | 
##               |     1.000 |     0.000 |     0.000 |     0.146 | 
##               |     0.476 |     0.000 |     0.000 |           | 
##               |     0.146 |     0.000 |     0.000 |           | 
## --------------|-----------|-----------|-----------|-----------|
##  Column Total |       168 |       320 |        60 |       548 | 
##               |     0.307 |     0.584 |     0.109 |           | 
## --------------|-----------|-----------|-----------|-----------|
## 
## 
profiling_num(raw0$SalesInThousands)
##   variable    mean  std_dev variation_coef    p_01    p_05   p_25 p_50    p_75
## 1      var 53.4662 16.75522      0.3133796 24.3154 30.6215 42.545 50.2 60.4775
##     p_95    p_99  skewness kurtosis     iqr           range_98         range_80
## 1 88.458 94.6738 0.8042872 3.152364 17.9325 [24.3154, 94.6738] [35.412, 82.266]

Splitting Data into Training and Validation:

set.seed(12345)

trainlm <- raw0 %>% 
  filter(random < 0.8) %>% 
  select(-random )

validationlm <- raw0 %>% 
  filter(random >= 0.8) %>% 
  select(-random )

Creating Initial Model and Selecting Appropriate Variables for the Model:

## 
## Call:
## lm(formula = SalesInThousands ~ ., data = trainlm)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -14.6813  -3.3325  -0.1337   3.1093  14.1222 
## 
## Coefficients: (2 not defined because of singularities)
##                    Estimate Std. Error t value Pr(>|t|)    
## (Intercept)       40.376472   1.053230  38.336  < 2e-16 ***
## MarketID2         25.763553   1.441758  17.870  < 2e-16 ***
## MarketID3         50.099687   1.027675  48.751  < 2e-16 ***
## MarketID4         19.347784   1.275623  15.167  < 2e-16 ***
## MarketID5         16.205559   1.098480  14.753  < 2e-16 ***
## MarketID6          2.037251   1.084460   1.879    0.061 .  
## MarketID7         10.606854   1.083625   9.788  < 2e-16 ***
## MarketID8         13.200319   1.154628  11.433  < 2e-16 ***
## MarketID9         17.673032   1.230141  14.367  < 2e-16 ***
## MarketID10        19.525676   1.009458  19.343  < 2e-16 ***
## MarketSizeMedium         NA         NA      NA       NA    
## MarketSizeSmall          NA         NA      NA       NA    
## AgeOfStore        -0.003655   0.037670  -0.097    0.923    
## Promotion2       -10.041430   0.620137 -16.192  < 2e-16 ***
## Promotion3        -5.039170   0.636692  -7.915 2.27e-14 ***
## Week              -0.166360   0.220784  -0.753    0.452    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 5.104 on 416 degrees of freedom
## Multiple R-squared:  0.9088, Adjusted R-squared:  0.906 
## F-statistic: 319.1 on 13 and 416 DF,  p-value: < 2.2e-16

Final Model with Significant Variables and Interpreting the Coefficients of the model.

## 
## Call:
## lm(formula = SalesInThousands ~ MarketID + Promotion, data = trainlm)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -14.5894  -3.3428  -0.1003   3.2096  14.2140 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  39.9386     0.8507  46.950  < 2e-16 ***
## MarketID2    25.7183     1.4281  18.008  < 2e-16 ***
## MarketID3    50.0952     1.0253  48.857  < 2e-16 ***
## MarketID4    19.3497     1.2734  15.195  < 2e-16 ***
## MarketID5    16.1848     1.0949  14.782  < 2e-16 ***
## MarketID6     2.0295     1.0825   1.875   0.0615 .  
## MarketID7    10.5980     1.0816   9.798  < 2e-16 ***
## MarketID8    13.1561     1.1427  11.513  < 2e-16 ***
## MarketID9    17.6263     1.2262  14.374  < 2e-16 ***
## MarketID10   19.5234     1.0068  19.392  < 2e-16 ***
## Promotion2  -10.0387     0.6190 -16.217  < 2e-16 ***
## Promotion3   -5.0267     0.6350  -7.916 2.23e-14 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 5.096 on 418 degrees of freedom
## Multiple R-squared:  0.9087, Adjusted R-squared:  0.9063 
## F-statistic: 378.3 on 11 and 418 DF,  p-value: < 2.2e-16

Testing Interactions Between Variables:

## 
## Call:
## lm(formula = SalesInThousands ~ (.)^2, data = trainlm)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -14.7173  -3.2565  -0.1168   3.2114  15.7946 
## 
## Coefficients: (29 not defined because of singularities)
##                             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                 44.60635    3.70737  12.032  < 2e-16 ***
## MarketID2                   18.03050    6.90821   2.610 0.009416 ** 
## MarketID3                   46.93987    3.99285  11.756  < 2e-16 ***
## MarketID4                    8.64526    4.53749   1.905 0.057504 .  
## MarketID5                   15.13694    4.62834   3.270 0.001173 ** 
## MarketID6                   -3.01540    4.17233  -0.723 0.470305    
## MarketID7                    8.90180    4.65345   1.913 0.056514 .  
## MarketID8                    8.26477    4.39165   1.882 0.060618 .  
## MarketID9                    6.77028    4.68005   1.447 0.148836    
## MarketID10                  13.68350    4.00424   3.417 0.000702 ***
## MarketSizeMedium                  NA         NA      NA       NA    
## MarketSizeSmall                   NA         NA      NA       NA    
## AgeOfStore                  -0.24500    0.26559  -0.922 0.356872    
## Promotion2                  -9.38912    2.76420  -3.397 0.000755 ***
## Promotion3                  -9.50224    2.98034  -3.188 0.001551 ** 
## Week                        -0.57790    0.80031  -0.722 0.470684    
## MarketID2:MarketSizeMedium        NA         NA      NA       NA    
## MarketID3:MarketSizeMedium        NA         NA      NA       NA    
## MarketID4:MarketSizeMedium        NA         NA      NA       NA    
## MarketID5:MarketSizeMedium        NA         NA      NA       NA    
## MarketID6:MarketSizeMedium        NA         NA      NA       NA    
## MarketID7:MarketSizeMedium        NA         NA      NA       NA    
## MarketID8:MarketSizeMedium        NA         NA      NA       NA    
## MarketID9:MarketSizeMedium        NA         NA      NA       NA    
## MarketID10:MarketSizeMedium       NA         NA      NA       NA    
## MarketID2:MarketSizeSmall         NA         NA      NA       NA    
## MarketID3:MarketSizeSmall         NA         NA      NA       NA    
## MarketID4:MarketSizeSmall         NA         NA      NA       NA    
## MarketID5:MarketSizeSmall         NA         NA      NA       NA    
## MarketID6:MarketSizeSmall         NA         NA      NA       NA    
## MarketID7:MarketSizeSmall         NA         NA      NA       NA    
## MarketID8:MarketSizeSmall         NA         NA      NA       NA    
## MarketID9:MarketSizeSmall         NA         NA      NA       NA    
## MarketID10:MarketSizeSmall        NA         NA      NA       NA    
## MarketID2:AgeOfStore         0.36669    0.32134   1.141 0.254553    
## MarketID3:AgeOfStore         0.08197    0.26494   0.309 0.757203    
## MarketID4:AgeOfStore         0.43623    0.27863   1.566 0.118272    
## MarketID5:AgeOfStore         0.22881    0.26792   0.854 0.393647    
## MarketID6:AgeOfStore         0.42755    0.27572   1.551 0.121827    
## MarketID7:AgeOfStore        -0.01964    0.29817  -0.066 0.947516    
## MarketID8:AgeOfStore         0.14006    0.26291   0.533 0.594534    
## MarketID9:AgeOfStore         0.51215    0.30601   1.674 0.095037 .  
## MarketID10:AgeOfStore        0.13564    0.26597   0.510 0.610351    
## MarketID2:Promotion2              NA         NA      NA       NA    
## MarketID3:Promotion2         1.20362    2.89574   0.416 0.677901    
## MarketID4:Promotion2         4.19112    3.00383   1.395 0.163761    
## MarketID5:Promotion2        -0.49693    3.29827  -0.151 0.880321    
## MarketID6:Promotion2         1.58319    2.77704   0.570 0.568951    
## MarketID7:Promotion2         0.41935    3.27729   0.128 0.898252    
## MarketID8:Promotion2         2.39968    3.12967   0.767 0.443711    
## MarketID9:Promotion2         4.67490    3.33406   1.402 0.161691    
## MarketID10:Promotion2        0.27141    2.56838   0.106 0.915896    
## MarketID2:Promotion3         6.29297    4.58590   1.372 0.170806    
## MarketID3:Promotion3         4.99323    2.87310   1.738 0.083043 .  
## MarketID4:Promotion3         7.00450    4.66881   1.500 0.134382    
## MarketID5:Promotion3         2.83457    3.68315   0.770 0.442019    
## MarketID6:Promotion3         3.78951    3.43239   1.104 0.270280    
## MarketID7:Promotion3         3.66743    3.12666   1.173 0.241557    
## MarketID8:Promotion3         7.29697    3.19481   2.284 0.022928 *  
## MarketID9:Promotion3         2.97228    3.35959   0.885 0.376874    
## MarketID10:Promotion3        3.82679    3.14627   1.216 0.224635    
## MarketID2:Week               0.37156    1.25334   0.296 0.767046    
## MarketID3:Week               0.40685    0.91043   0.447 0.655220    
## MarketID4:Week               1.71023    1.14705   1.491 0.136805    
## MarketID5:Week              -0.12308    0.97234  -0.127 0.899339    
## MarketID6:Week               0.03055    0.98913   0.031 0.975375    
## MarketID7:Week               0.41412    0.97465   0.425 0.671158    
## MarketID8:Week               0.37061    1.02380   0.362 0.717561    
## MarketID9:Week               1.95631    1.08603   1.801 0.072449 .  
## MarketID10:Week              1.59633    0.90246   1.769 0.077728 .  
## MarketSizeMedium:AgeOfStore       NA         NA      NA       NA    
## MarketSizeSmall:AgeOfStore        NA         NA      NA       NA    
## MarketSizeMedium:Promotion2       NA         NA      NA       NA    
## MarketSizeSmall:Promotion2        NA         NA      NA       NA    
## MarketSizeMedium:Promotion3       NA         NA      NA       NA    
## MarketSizeSmall:Promotion3        NA         NA      NA       NA    
## MarketSizeMedium:Week             NA         NA      NA       NA    
## MarketSizeSmall:Week              NA         NA      NA       NA    
## AgeOfStore:Promotion2       -0.11635    0.12461  -0.934 0.351050    
## AgeOfStore:Promotion3        0.10674    0.11699   0.912 0.362160    
## AgeOfStore:Week              0.01458    0.03375   0.432 0.666006    
## Promotion2:Week             -0.55491    0.55942  -0.992 0.321864    
## Promotion3:Week             -0.48595    0.57671  -0.843 0.399979    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 5.093 on 376 degrees of freedom
## Multiple R-squared:  0.918,  Adjusted R-squared:  0.9064 
## F-statistic: 79.41 on 53 and 376 DF,  p-value: < 2.2e-16
## Backward Elimination Method 
## ---------------------------
## 
## Candidate Terms: 
## 
## 1 . MarketID 
## 2 . MarketSize 
## 3 . AgeOfStore 
## 4 . Promotion 
## 5 . Week 
## 6 . MarketID:MarketSize 
## 7 . MarketID:AgeOfStore 
## 8 . MarketID:Promotion 
## 9 . MarketID:Week 
## 10 . MarketSize:AgeOfStore 
## 11 . MarketSize:Promotion 
## 12 . MarketSize:Week 
## 13 . AgeOfStore:Promotion 
## 14 . AgeOfStore:Week 
## 15 . Promotion:Week 
## 
## We are eliminating variables based on p value...
## 
## - AgeOfStore 
## 
## Backward Elimination: Step 1 
## 
##  Variable AgeOfStore Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.958       RMSE                5.093 
## R-Squared               0.918       Coef. Var           9.574 
## Adj. R-Squared          0.906       MSE                25.935 
## Pred R-Squared          0.894       MAE                 3.777 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                  
## -----------------------------------------------------------------------
##                   Sum of                                               
##                  Squares         DF    Mean Square      F         Sig. 
## -----------------------------------------------------------------------
## Regression    109154.818         53       2059.525     79.41    0.0000 
## Residual        9751.669        376         25.935                     
## Total         118906.487        429                                    
## -----------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    44.606         3.707                 12.032    0.000     37.317    51.896 
##                   MarketID2    18.031         6.908        0.228     2.610    0.009      4.447    31.614 
##                   MarketID3    46.940         3.993        1.005    11.756    0.000     39.089    54.791 
##                   MarketID4     8.645         4.537        0.124     1.905    0.058     -0.277    17.567 
##                   MarketID5    15.137         4.628        0.284     3.270    0.001      6.036    24.238 
##                   MarketID6    -3.015         4.172       -0.057    -0.723    0.470    -11.219     5.189 
##                   MarketID7     8.902         4.653        0.170     1.913    0.057     -0.248    18.052 
##                   MarketID8     8.265         4.392        0.143     1.882    0.061     -0.370    16.900 
##                   MarketID9     6.770         4.680        0.104     1.447    0.149     -2.432    15.973 
##                  MarketID10    13.683         4.004        0.297     3.417    0.001      5.810    21.557 
##            MarketSizeMedium        NA         2.764       -0.278    -3.397    0.001         NA        NA 
##             MarketSizeSmall        NA         2.980       -0.177    -3.188    0.002         NA        NA 
##                  Promotion2    -9.389         0.800       -0.017    -0.722    0.471    -14.824    -3.954 
##                  Promotion3    -9.502         0.266       -0.007    -0.922    0.357    -15.362    -3.642 
##                        Week    -0.578         0.242        0.008     0.503    0.615     -2.152     0.996 
##  MarketID2:MarketSizeMedium        NA         0.152        0.000    -1.076    0.283         NA        NA 
##  MarketID3:MarketSizeMedium        NA         0.194        0.000     0.986    0.325         NA        NA 
##  MarketID4:MarketSizeMedium        NA         0.180        0.000    -0.090    0.928         NA        NA 
##  MarketID5:MarketSizeMedium        NA         0.184        0.003     0.990    0.323         NA        NA 
##  MarketID6:MarketSizeMedium        NA         0.193       -0.005    -1.369    0.172         NA        NA 
##  MarketID7:MarketSizeMedium        NA         0.146       -0.002    -0.720    0.472         NA        NA 
##  MarketID8:MarketSizeMedium        NA         0.219        0.005     1.221    0.223         NA        NA 
##  MarketID9:MarketSizeMedium        NA         0.138       -0.002    -0.793    0.428         NA        NA 
## MarketID10:MarketSizeMedium        NA         2.896        0.000     0.416    0.678         NA        NA 
##   MarketID2:MarketSizeSmall        NA         3.004        0.053     1.395    0.164         NA        NA 
##   MarketID3:MarketSizeSmall        NA         3.298        0.000    -0.151    0.880         NA        NA 
##   MarketID4:MarketSizeSmall        NA         2.777        0.023     0.570    0.569         NA        NA 
##   MarketID5:MarketSizeSmall        NA         3.277        0.000     0.128    0.898         NA        NA 
##   MarketID6:MarketSizeSmall        NA         3.130        0.000     0.767    0.444         NA        NA 
##   MarketID7:MarketSizeSmall        NA         3.334        0.000     1.402    0.162         NA        NA 
##   MarketID8:MarketSizeSmall        NA         2.568        0.000     0.106    0.916         NA        NA 
##   MarketID9:MarketSizeSmall        NA         4.586        0.000     1.372    0.171         NA        NA 
##  MarketID10:MarketSizeSmall        NA         2.873        0.000     1.738    0.083         NA        NA 
##        MarketID1:AgeOfStore    -0.245         4.669        1.170     1.500    0.134     -0.767     0.277 
##        MarketID2:AgeOfStore     0.122         3.683        0.551     0.770    0.442     -0.354     0.597 
##        MarketID3:AgeOfStore    -0.163         3.432        0.838     1.104    0.270     -0.461     0.135 
##        MarketID4:AgeOfStore     0.191         3.127        0.609     1.173    0.242     -0.190     0.573 
##        MarketID5:AgeOfStore    -0.016         3.195        1.700     2.284    0.023     -0.370     0.337 
##        MarketID6:AgeOfStore     0.183         3.360        0.613     0.885    0.377     -0.180     0.545 
##        MarketID7:AgeOfStore    -0.265         3.146        0.725     1.216    0.225     -0.645     0.115 
##        MarketID8:AgeOfStore    -0.105         1.253        0.101     0.296    0.767     -0.392     0.182 
##        MarketID9:AgeOfStore     0.267         0.910        0.062     0.447    0.655     -0.163     0.697 
##       MarketID10:AgeOfStore    -0.109         1.147        0.359     1.491    0.137     -0.381     0.162 
##        MarketID2:Promotion2        NA         0.972        0.000    -0.127    0.899         NA        NA 
##        MarketID3:Promotion2     1.204         0.989        0.000     0.031    0.975     -4.490     6.897 
##        MarketID4:Promotion2     4.191         0.975        0.004     0.425    0.671     -1.715    10.098 
##        MarketID5:Promotion2    -0.497         1.024        0.006     0.362    0.718     -6.982     5.988 
##        MarketID6:Promotion2     1.583         1.086        0.025     1.801    0.072     -3.877     7.044 
##        MarketID7:Promotion2     0.419         0.902        0.016     1.769    0.078     -6.025     6.863 
##        MarketID8:Promotion2     2.400         0.125       -0.001    -0.934    0.351     -3.754     8.554 
##        MarketID9:Promotion2     4.675         0.117        0.001     0.912    0.362     -1.881    11.231 
##       MarketID10:Promotion2     0.271         0.034        0.000     0.432    0.666     -4.779     5.322 
##        MarketID2:Promotion3     6.293         0.559       -0.006    -0.992    0.322     -2.724    15.310 
##        MarketID3:Promotion3     4.993         0.577       -0.007    -0.843    0.400     -0.656    10.643 
##        MarketID4:Promotion3     7.004            NA        0.074        NA       NA     -2.176    16.185 
##        MarketID5:Promotion3     2.835            NA        0.465        NA       NA     -4.408    10.077 
##        MarketID6:Promotion3     3.790            NA        0.078        NA       NA     -2.960    10.539 
##        MarketID7:Promotion3     3.667            NA        0.201        NA       NA     -2.481     9.815 
##        MarketID8:Promotion3     7.297            NA       -0.035        NA       NA      1.015    13.579 
##        MarketID9:Promotion3     2.972            NA        0.092        NA       NA     -3.634     9.578 
##       MarketID10:Promotion3     3.827            NA        0.075        NA       NA     -2.360    10.013 
##              MarketID2:Week     0.372            NA        0.241        NA       NA     -2.093     2.836 
##              MarketID3:Week     0.407            NA        0.801        NA       NA     -1.383     2.197 
##              MarketID4:Week     1.710            NA       -0.361        NA       NA     -0.545     3.966 
##              MarketID5:Week    -0.123            NA       -0.497        NA       NA     -2.035     1.789 
##              MarketID6:Week     0.031            NA       -0.029        NA       NA     -1.914     1.975 
##              MarketID7:Week     0.414            NA       -0.013        NA       NA     -1.502     2.331 
##              MarketID8:Week     0.371            NA        0.006        NA       NA     -1.642     2.384 
##              MarketID9:Week     1.956            NA       -0.007        NA       NA     -0.179     4.092 
##             MarketID10:Week     1.596            NA        0.011        NA       NA     -0.178     3.371 
## MarketSizeMedium:AgeOfStore        NA            NA       -0.007        NA       NA         NA        NA 
##  MarketSizeSmall:AgeOfStore        NA            NA        0.046        NA       NA         NA        NA 
## MarketSizeMedium:Promotion2        NA            NA       -0.007        NA       NA         NA        NA 
##  MarketSizeSmall:Promotion2        NA            NA       -0.001        NA       NA         NA        NA 
## MarketSizeMedium:Promotion3        NA            NA        0.006        NA       NA         NA        NA 
##  MarketSizeSmall:Promotion3        NA            NA       -0.001        NA       NA         NA        NA 
##       MarketSizeMedium:Week        NA            NA        0.109        NA       NA         NA        NA 
##        MarketSizeSmall:Week        NA            NA        0.215        NA       NA         NA        NA 
##       Promotion2:AgeOfStore    -0.116            NA       -0.168        NA       NA     -0.361     0.129 
##       Promotion3:AgeOfStore     0.107            NA        0.564        NA       NA     -0.123     0.337 
##             Week:AgeOfStore     0.015            NA        0.536        NA       NA     -0.052     0.081 
##             Promotion2:Week    -0.555            NA        0.197        NA       NA     -1.655     0.545 
##             Promotion3:Week    -0.486            NA        0.372        NA       NA     -1.620     0.648 
## ---------------------------------------------------------------------------------------------------------
## 
## 
## - MarketID:Promotion 
## 
## Backward Elimination: Step 2 
## 
##  Variable MarketID:Promotion Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.957       RMSE                5.070 
## R-Squared               0.916       Coef. Var           9.532 
## Adj. R-Squared          0.907       MSE                25.708 
## Pred R-Squared          0.898       MAE                 3.873 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108906.036         40       2722.651    105.906    0.0000 
## Residual       10000.451        389         25.708                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    41.861         2.913                 14.372    0.000     36.135    47.588 
##                   MarketID2    21.022         5.581        0.266     3.767    0.000     10.049    31.995 
##                   MarketID3    50.103         3.236        1.072    15.484    0.000     43.741    56.465 
##                   MarketID4    11.459         3.932        0.164     2.914    0.004      3.728    19.190 
##                   MarketID5    16.478         3.213        0.309     5.129    0.000     10.161    22.795 
##                   MarketID6    -0.083         3.304       -0.002    -0.025    0.980     -6.580     6.414 
##                   MarketID7    11.072         3.253        0.212     3.403    0.001      4.676    17.469 
##                   MarketID8    12.340         3.465        0.213     3.561    0.000      5.527    19.153 
##                   MarketID9    11.102         3.787        0.170     2.932    0.004      3.656    18.548 
##                  MarketID10    16.189         3.229        0.351     5.013    0.000      9.840    22.538 
##            MarketSizeMedium        NA         1.986       -0.260    -4.424    0.000         NA        NA 
##             MarketSizeSmall        NA         1.899       -0.100    -2.843    0.005         NA        NA 
##                  Promotion2    -8.787         0.795       -0.015    -0.645    0.519    -12.692    -4.882 
##                  Promotion3    -5.400         0.224       -0.003    -0.399    0.690     -9.134    -1.665 
##                        Week    -0.513         0.214        0.007     0.490    0.625     -2.075     1.050 
##  MarketID2:MarketSizeMedium        NA         0.147        0.000    -1.133    0.258         NA        NA 
##  MarketID3:MarketSizeMedium        NA         0.190        0.000     1.042    0.298         NA        NA 
##  MarketID4:MarketSizeMedium        NA         0.175        0.000    -0.184    0.854         NA        NA 
##  MarketID5:MarketSizeMedium        NA         0.169        0.003     0.978    0.328         NA        NA 
##  MarketID6:MarketSizeMedium        NA         0.168       -0.004    -1.356    0.176         NA        NA 
##  MarketID7:MarketSizeMedium        NA         0.142       -0.001    -0.460    0.646         NA        NA 
##  MarketID8:MarketSizeMedium        NA         0.205        0.003     0.779    0.437         NA        NA 
##  MarketID9:MarketSizeMedium        NA         0.136       -0.002    -0.832    0.406         NA        NA 
## MarketID10:MarketSizeMedium        NA         1.245        0.000     0.222    0.824         NA        NA 
##   MarketID2:MarketSizeSmall        NA         0.904        0.004     0.356    0.722         NA        NA 
##   MarketID3:MarketSizeSmall        NA         1.138        0.000     1.455    0.147         NA        NA 
##   MarketID4:MarketSizeSmall        NA         0.963       -0.002    -0.163    0.871         NA        NA 
##   MarketID5:MarketSizeSmall        NA         0.977        0.000    -0.043    0.965         NA        NA 
##   MarketID6:MarketSizeSmall        NA         0.967        0.000     0.345    0.730         NA        NA 
##   MarketID7:MarketSizeSmall        NA         1.016        0.000     0.212    0.832         NA        NA 
##   MarketID8:MarketSizeSmall        NA         1.078        0.000     1.620    0.106         NA        NA 
##   MarketID9:MarketSizeSmall        NA         0.895        0.000     1.706    0.089         NA        NA 
##  MarketID10:MarketSizeSmall        NA         1.424        0.000     0.563    0.574         NA        NA 
##        MarketID1:AgeOfStore    -0.089         2.335        0.569     1.460    0.145     -0.530     0.351 
##        MarketID2:AgeOfStore     0.105         1.460       -0.134    -0.473    0.637     -0.316     0.525 
##        MarketID3:AgeOfStore    -0.166         3.006        0.382     0.575    0.566     -0.455     0.122 
##        MarketID4:AgeOfStore     0.198         0.117       -0.020    -1.017    0.310     -0.175     0.571 
##        MarketID5:AgeOfStore    -0.032         0.106        0.034     1.379    0.169     -0.376     0.312 
##        MarketID6:AgeOfStore     0.165         0.034        0.003     0.381    0.703     -0.167     0.497 
##        MarketID7:AgeOfStore    -0.228         0.556       -0.097    -0.925    0.355     -0.558     0.103 
##        MarketID8:AgeOfStore    -0.065         0.570       -0.115    -0.744    0.457     -0.343     0.213 
##        MarketID9:AgeOfStore     0.160            NA        3.183        NA       NA     -0.244     0.563 
##       MarketID10:AgeOfStore    -0.113            NA       10.518        NA       NA     -0.381     0.155 
##              MarketID2:Week     0.277            NA        0.408        NA       NA     -2.171     2.726 
##              MarketID3:Week     0.322            NA        0.965        NA       NA     -1.455     2.099 
##              MarketID4:Week     1.655            NA       -0.003        NA       NA     -0.582     3.892 
##              MarketID5:Week    -0.157            NA        0.579        NA       NA     -2.051     1.737 
##              MarketID6:Week    -0.042            NA        0.629        NA       NA     -1.964     1.879 
##              MarketID7:Week     0.334            NA        0.579        NA       NA     -1.568     2.236 
##              MarketID8:Week     0.215            NA        0.796        NA       NA     -1.782     2.213 
##              MarketID9:Week     1.747            NA       -0.396        NA       NA     -0.373     3.867 
##             MarketID10:Week     1.528            NA       -0.321        NA       NA     -0.232     3.288 
## MarketSizeMedium:AgeOfStore        NA            NA       -0.211        NA       NA         NA        NA 
##  MarketSizeSmall:AgeOfStore        NA            NA       -0.022        NA       NA         NA        NA 
## MarketSizeMedium:Promotion2     0.802            NA        0.003        NA       NA     -1.998     3.601 
##  MarketSizeSmall:Promotion2     3.408            NA       -0.002        NA       NA     -1.182     7.999 
## MarketSizeMedium:Promotion3    -0.690            NA        0.005        NA       NA     -3.560     2.180 
##  MarketSizeSmall:Promotion3     1.728            NA        0.000        NA       NA     -4.182     7.639 
##       MarketSizeMedium:Week        NA            NA        0.015        NA       NA         NA        NA 
##        MarketSizeSmall:Week        NA            NA       -0.012        NA       NA         NA        NA 
##       Promotion2:AgeOfStore    -0.119            NA       -0.022        NA       NA     -0.350     0.111 
##       Promotion3:AgeOfStore     0.147            NA        0.057        NA       NA     -0.063     0.356 
##             Week:AgeOfStore     0.013            NA       -0.145        NA       NA     -0.053     0.079 
##             Promotion2:Week    -0.514            NA        0.023        NA       NA     -1.607     0.579 
##             Promotion3:Week    -0.424            NA        0.026        NA       NA     -1.544     0.696 
## ---------------------------------------------------------------------------------------------------------
## 
## 
## - AgeOfStore:Week 
## 
## Backward Elimination: Step 3 
## 
##  Variable AgeOfStore:Week Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.957       RMSE                5.065 
## R-Squared               0.916       Coef. Var           9.521 
## Adj. R-Squared          0.907       MSE                25.652 
## Pred R-Squared          0.899       MAE                 3.875 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108902.301         39       2792.367    108.857    0.0000 
## Residual       10004.185        390         25.652                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    41.597         2.826                 14.720    0.000     36.041    47.153 
##                   MarketID2    20.863         5.559        0.264     3.753    0.000      9.933    31.793 
##                   MarketID3    50.140         3.231        1.073    15.519    0.000     43.788    56.492 
##                   MarketID4    11.460         3.928        0.164     2.917    0.004      3.737    19.182 
##                   MarketID5    16.433         3.207        0.308     5.124    0.000     10.128    22.739 
##                   MarketID6    -0.103         3.300       -0.002    -0.031    0.975     -6.592     6.385 
##                   MarketID7    11.092         3.249        0.212     3.414    0.001      4.704    17.481 
##                   MarketID8    12.197         3.441        0.211     3.544    0.000      5.432    18.963 
##                   MarketID9    11.084         3.783        0.170     2.930    0.004      3.647    18.521 
##                  MarketID10    16.235         3.223        0.352     5.037    0.000      9.898    22.573 
##            MarketSizeMedium        NA         1.984       -0.259    -4.421    0.000         NA        NA 
##             MarketSizeSmall        NA         1.897       -0.100    -2.849    0.005         NA        NA 
##                  Promotion2    -8.769         0.746       -0.012    -0.549    0.584    -12.669    -4.869 
##                  Promotion3    -5.405         0.207       -0.002    -0.276    0.783     -9.135    -1.675 
##                        Week    -0.409         0.196        0.009     0.702    0.483     -1.876     1.057 
##  MarketID2:MarketSizeMedium        NA         0.122        0.000    -1.108    0.268         NA        NA 
##  MarketID3:MarketSizeMedium        NA         0.170        0.000     1.350    0.178         NA        NA 
##  MarketID4:MarketSizeMedium        NA         0.151        0.000     0.010    0.992         NA        NA 
##  MarketID5:MarketSizeMedium        NA         0.144        0.004     1.371    0.171         NA        NA 
##  MarketID6:MarketSizeMedium        NA         0.145       -0.004    -1.347    0.179         NA        NA 
##  MarketID7:MarketSizeMedium        NA         0.108       -0.001    -0.280    0.780         NA        NA 
##  MarketID8:MarketSizeMedium        NA         0.180        0.003     1.097    0.273         NA        NA 
##  MarketID9:MarketSizeMedium        NA         0.109       -0.001    -0.755    0.451         NA        NA 
## MarketID10:MarketSizeMedium        NA         1.233        0.000     0.276    0.783         NA        NA 
##   MarketID2:MarketSizeSmall        NA         0.902        0.004     0.345    0.731         NA        NA 
##   MarketID3:MarketSizeSmall        NA         1.137        0.000     1.460    0.145         NA        NA 
##   MarketID4:MarketSizeSmall        NA         0.961       -0.002    -0.142    0.887         NA        NA 
##   MarketID5:MarketSizeSmall        NA         0.976        0.000    -0.035    0.972         NA        NA 
##   MarketID6:MarketSizeSmall        NA         0.966        0.000     0.340    0.734         NA        NA 
##   MarketID7:MarketSizeSmall        NA         1.007        0.000     0.260    0.795         NA        NA 
##   MarketID8:MarketSizeSmall        NA         1.077        0.000     1.614    0.107         NA        NA 
##   MarketID9:MarketSizeSmall        NA         0.893        0.000     1.693    0.091         NA        NA 
##  MarketID10:MarketSizeSmall        NA         1.422        0.000     0.556    0.579         NA        NA 
##        MarketID1:AgeOfStore    -0.057         2.332        0.567     1.455    0.146     -0.465     0.351 
##        MarketID2:AgeOfStore     0.137         1.458       -0.134    -0.474    0.636     -0.247     0.522 
##        MarketID3:AgeOfStore    -0.135         3.003        0.381     0.574    0.566     -0.375     0.105 
##        MarketID4:AgeOfStore     0.230         0.117       -0.020    -1.036    0.301     -0.105     0.564 
##        MarketID5:AgeOfStore     0.002         0.106        0.034     1.370    0.172     -0.295     0.298 
##        MarketID6:AgeOfStore     0.198         0.555       -0.106    -0.922    0.357     -0.086     0.482 
##        MarketID7:AgeOfStore    -0.196         0.569       -0.079    -0.733    0.464     -0.481     0.090 
##        MarketID8:AgeOfStore    -0.030            NA        5.652        NA       NA     -0.242     0.182 
##        MarketID9:AgeOfStore     0.197            NA        7.592        NA       NA     -0.156     0.551 
##       MarketID10:AgeOfStore    -0.082            NA        2.406        NA       NA     -0.296     0.132 
##              MarketID2:Week     0.340            NA        0.586        NA       NA     -2.084     2.764 
##              MarketID3:Week     0.311            NA       -0.006        NA       NA     -1.463     2.085 
##              MarketID4:Week     1.660            NA        0.426        NA       NA     -0.575     3.894 
##              MarketID5:Week    -0.136            NA        0.638        NA       NA     -2.025     1.753 
##              MarketID6:Week    -0.034            NA        0.565        NA       NA     -1.953     1.885 
##              MarketID7:Week     0.329            NA        0.846        NA       NA     -1.571     2.228 
##              MarketID8:Week     0.262            NA       -0.431        NA       NA     -1.718     2.243 
##              MarketID9:Week     1.737            NA       -0.244        NA       NA     -0.379     3.854 
##             MarketID10:Week     1.512            NA       -0.024        NA       NA     -0.244     3.269 
## MarketSizeMedium:AgeOfStore        NA            NA       -0.023        NA       NA         NA        NA 
##  MarketSizeSmall:AgeOfStore        NA            NA        0.034        NA       NA         NA        NA 
## MarketSizeMedium:Promotion2     0.790            NA       -0.003        NA       NA     -2.005     3.586 
##  MarketSizeSmall:Promotion2     3.394            NA        0.002        NA       NA     -1.191     7.978 
## MarketSizeMedium:Promotion3    -0.691            NA        0.000        NA       NA     -3.559     2.176 
##  MarketSizeSmall:Promotion3     1.723            NA        0.002        NA       NA     -4.181     7.628 
##       MarketSizeMedium:Week        NA            NA       -0.018        NA       NA         NA        NA 
##        MarketSizeSmall:Week        NA            NA       -0.002        NA       NA         NA        NA 
##       Promotion2:AgeOfStore    -0.121            NA        0.067        NA       NA     -0.352     0.109 
##       Promotion3:AgeOfStore     0.146            NA       -0.029        NA       NA     -0.063     0.355 
##             Promotion2:Week    -0.512            NA        0.028        NA       NA     -1.604     0.580 
##             Promotion3:Week    -0.417            NA        0.025        NA       NA     -1.535     0.701 
## ---------------------------------------------------------------------------------------------------------
## 
## 
## - Promotion:Week 
## 
## Backward Elimination: Step 4 
## 
##  Variable Promotion:Week Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.957       RMSE                5.058 
## R-Squared               0.916       Coef. Var           9.509 
## Adj. R-Squared          0.908       MSE                25.585 
## Pred R-Squared          0.899       MAE                 3.873 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108877.331         37       2942.631    115.016    0.0000 
## Residual       10029.155        392         25.585                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                             
## ----------------------------------------------------------------------------------------------------------
##                       model       Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ----------------------------------------------------------------------------------------------------------
##                 (Intercept)     42.341         2.718                 15.579    0.000     36.998    47.684 
##                   MarketID2     20.979         5.497        0.266     3.816    0.000     10.172    31.787 
##                   MarketID3     50.109         3.218        1.073    15.572    0.000     43.782    56.435 
##                   MarketID4     11.426         3.913        0.164     2.920    0.004      3.733    19.119 
##                   MarketID5     16.797         3.180        0.315     5.282    0.000     10.545    23.049 
##                   MarketID6     -0.071         3.295       -0.001    -0.022    0.983     -6.549     6.407 
##                   MarketID7     11.190         3.236        0.214     3.459    0.001      4.829    17.551 
##                   MarketID8     12.254         3.426        0.212     3.576    0.000      5.517    18.990 
##                   MarketID9     11.179         3.770        0.171     2.965    0.003      3.767    18.591 
##                  MarketID10     16.209         3.212        0.351     5.046    0.000      9.893    22.524 
##            MarketSizeMedium         NA         1.438       -0.297    -6.979    0.000         NA        NA 
##             MarketSizeSmall         NA         1.341       -0.119    -4.775    0.000         NA        NA 
##                  Promotion2    -10.036         0.688       -0.020    -1.006    0.315    -12.863    -7.209 
##                  Promotion3     -6.404         0.207       -0.002    -0.289    0.773     -9.040    -3.767 
##                        Week     -0.692         0.195        0.009     0.703    0.483     -2.044     0.661 
##  MarketID2:MarketSizeMedium         NA         0.122        0.000    -1.121    0.263         NA        NA 
##  MarketID3:MarketSizeMedium         NA         0.170        0.000     1.370    0.171         NA        NA 
##  MarketID4:MarketSizeMedium         NA         0.150        0.000     0.022    0.983         NA        NA 
##  MarketID5:MarketSizeMedium         NA         0.144        0.004     1.380    0.168         NA        NA 
##  MarketID6:MarketSizeMedium         NA         0.145       -0.004    -1.368    0.172         NA        NA 
##  MarketID7:MarketSizeMedium         NA         0.108       -0.001    -0.265    0.791         NA        NA 
##  MarketID8:MarketSizeMedium         NA         0.179        0.003     1.076    0.283         NA        NA 
##  MarketID9:MarketSizeMedium         NA         0.109       -0.001    -0.746    0.456         NA        NA 
## MarketID10:MarketSizeMedium         NA         1.193        0.000     0.238    0.812         NA        NA 
##   MarketID2:MarketSizeSmall         NA         0.891        0.004     0.339    0.735         NA        NA 
##   MarketID3:MarketSizeSmall         NA         1.132        0.000     1.451    0.148         NA        NA 
##   MarketID4:MarketSizeSmall         NA         0.948       -0.004    -0.297    0.767         NA        NA 
##   MarketID5:MarketSizeSmall         NA         0.974        0.000    -0.056    0.955         NA        NA 
##   MarketID6:MarketSizeSmall         NA         0.956        0.000     0.314    0.754         NA        NA 
##   MarketID7:MarketSizeSmall         NA         0.996        0.000     0.237    0.813         NA        NA 
##   MarketID8:MarketSizeSmall         NA         1.069        0.000     1.599    0.111         NA        NA 
##   MarketID9:MarketSizeSmall         NA         0.891        0.000     1.684    0.093         NA        NA 
##  MarketID10:MarketSizeSmall         NA         1.419        0.000     0.524    0.600         NA        NA 
##        MarketID1:AgeOfStore     -0.060         2.328        0.576     1.480    0.140     -0.467     0.347 
##        MarketID2:AgeOfStore      0.137         1.454       -0.148    -0.524    0.601     -0.247     0.521 
##        MarketID3:AgeOfStore     -0.137         2.995        0.369     0.557    0.578     -0.376     0.103 
##        MarketID4:AgeOfStore      0.233         0.117       -0.020    -1.049    0.295     -0.101     0.566 
##        MarketID5:AgeOfStore      0.003         0.106        0.034     1.366    0.173     -0.292     0.299 
##        MarketID6:AgeOfStore      0.199            NA        4.324        NA       NA     -0.084     0.483 
##        MarketID7:AgeOfStore     -0.198            NA        9.497        NA       NA     -0.484     0.087 
##        MarketID8:AgeOfStore     -0.029            NA        3.095        NA       NA     -0.240     0.183 
##        MarketID9:AgeOfStore      0.193            NA        2.543        NA       NA     -0.160     0.546 
##       MarketID10:AgeOfStore     -0.081            NA       -0.015        NA       NA     -0.294     0.132 
##              MarketID2:Week      0.284            NA        0.399        NA       NA     -2.061     2.629 
##              MarketID3:Week      0.302            NA        0.717        NA       NA     -1.450     2.054 
##              MarketID4:Week      1.642            NA        0.430        NA       NA     -0.583     3.867 
##              MarketID5:Week     -0.282            NA        0.848        NA       NA     -2.145     1.582 
##              MarketID6:Week     -0.055            NA       -0.511        NA       NA     -1.970     1.861 
##              MarketID7:Week      0.300            NA       -0.334        NA       NA     -1.579     2.180 
##              MarketID8:Week      0.236            NA       -0.034        NA       NA     -1.723     2.194 
##              MarketID9:Week      1.710            NA       -0.003        NA       NA     -0.393     3.813 
##             MarketID10:Week      1.500            NA        0.008        NA       NA     -0.251     3.251 
## MarketSizeMedium:AgeOfStore         NA            NA       -0.056        NA       NA         NA        NA 
##  MarketSizeSmall:AgeOfStore         NA            NA        0.058        NA       NA         NA        NA 
## MarketSizeMedium:Promotion2      0.744            NA        0.000        NA       NA     -2.046     3.534 
##  MarketSizeSmall:Promotion2      3.446            NA        0.002        NA       NA     -1.131     8.024 
## MarketSizeMedium:Promotion3     -0.762            NA       -0.005        NA       NA     -3.620     2.097 
##  MarketSizeSmall:Promotion3      1.669            NA        0.000        NA       NA     -4.219     7.556 
##       MarketSizeMedium:Week         NA            NA        0.017        NA       NA         NA        NA 
##        MarketSizeSmall:Week         NA            NA       -0.004        NA       NA         NA        NA 
##       Promotion2:AgeOfStore     -0.123            NA        0.096        NA       NA     -0.352     0.107 
##       Promotion3:AgeOfStore      0.145            NA        0.108        NA       NA     -0.064     0.354 
## ----------------------------------------------------------------------------------------------------------
## 
## 
## - MarketSize:Promotion 
## 
## Backward Elimination: Step 5 
## 
##  Variable MarketSize:Promotion Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.957       RMSE                5.053 
## R-Squared               0.915       Coef. Var           9.499 
## Adj. R-Squared          0.908       MSE                25.533 
## Pred R-Squared          0.900       MAE                 3.891 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108795.553         33       3296.835    129.122    0.0000 
## Residual       10110.934        396         25.533                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    42.102         2.630                 16.008    0.000     36.931    47.273 
##                   MarketID2    23.673         4.296        0.300     5.511    0.000     15.228    32.119 
##                   MarketID3    50.546         3.056        1.082    16.541    0.000     44.538    56.554 
##                   MarketID4    13.187         3.622        0.189     3.641    0.000      6.066    20.308 
##                   MarketID5    16.892         3.172        0.317     5.325    0.000     10.655    23.129 
##                   MarketID6     0.125         3.270        0.002     0.038    0.970     -6.304     6.553 
##                   MarketID7    11.139         3.231        0.213     3.448    0.001      4.788    17.490 
##                   MarketID8    12.368         3.409        0.214     3.629    0.000      5.667    19.069 
##                   MarketID9    11.391         3.750        0.175     3.038    0.003      4.019    18.764 
##                  MarketID10    16.252         3.037        0.352     5.352    0.000     10.282    22.223 
##            MarketSizeMedium        NA         1.094       -0.273    -8.431    0.000         NA        NA 
##             MarketSizeSmall        NA         1.111       -0.126    -6.122    0.000         NA        NA 
##                  Promotion2    -9.223         0.687       -0.020    -0.991    0.322    -11.374    -7.073 
##                  Promotion3    -6.798         0.202       -0.001    -0.238    0.812     -8.982    -4.615 
##                        Week    -0.681         0.167        0.005     0.404    0.686     -2.031     0.670 
##  MarketID2:MarketSizeMedium        NA         0.119        0.000    -1.324    0.186         NA        NA 
##  MarketID3:MarketSizeMedium        NA         0.167        0.000     1.436    0.152         NA        NA 
##  MarketID4:MarketSizeMedium        NA         0.147        0.000     0.019    0.985         NA        NA 
##  MarketID5:MarketSizeMedium        NA         0.142        0.003     1.279    0.202         NA        NA 
##  MarketID6:MarketSizeMedium        NA         0.142       -0.004    -1.359    0.175         NA        NA 
##  MarketID7:MarketSizeMedium        NA         0.106       -0.001    -0.403    0.687         NA        NA 
##  MarketID8:MarketSizeMedium        NA         0.178        0.003     0.968    0.333         NA        NA 
##  MarketID9:MarketSizeMedium        NA         0.108       -0.001    -0.833    0.406         NA        NA 
## MarketID10:MarketSizeMedium        NA         1.191        0.000     0.238    0.812         NA        NA 
##   MarketID2:MarketSizeSmall        NA         0.890        0.003     0.304    0.761         NA        NA 
##   MarketID3:MarketSizeSmall        NA         1.124        0.000     1.405    0.161         NA        NA 
##   MarketID4:MarketSizeSmall        NA         0.946       -0.004    -0.320    0.749         NA        NA 
##   MarketID5:MarketSizeSmall        NA         0.973        0.000    -0.047    0.962         NA        NA 
##   MarketID6:MarketSizeSmall        NA         0.955        0.000     0.313    0.754         NA        NA 
##   MarketID7:MarketSizeSmall        NA         0.995        0.000     0.241    0.809         NA        NA 
##   MarketID8:MarketSizeSmall        NA         1.068        0.000     1.577    0.116         NA        NA 
##   MarketID9:MarketSizeSmall        NA         0.888        0.000     1.631    0.104         NA        NA 
##  MarketID10:MarketSizeSmall        NA         0.114        0.000    -1.061    0.289         NA        NA 
##        MarketID1:AgeOfStore    -0.048         0.100        0.026     1.562    0.119     -0.446     0.350 
##        MarketID2:AgeOfStore     0.067            NA        4.601        NA       NA     -0.260     0.395 
##        MarketID3:AgeOfStore    -0.158            NA       11.175        NA       NA     -0.392     0.076 
##        MarketID4:AgeOfStore     0.240            NA        2.188        NA       NA     -0.089     0.569 
##        MarketID5:AgeOfStore     0.003            NA        3.935        NA       NA     -0.287     0.292 
##        MarketID6:AgeOfStore     0.181            NA        0.026        NA       NA     -0.097     0.460 
##        MarketID7:AgeOfStore    -0.193            NA        2.111        NA       NA     -0.473     0.086 
##        MarketID8:AgeOfStore    -0.043            NA        3.351        NA       NA     -0.251     0.166 
##        MarketID9:AgeOfStore     0.172            NA        1.725        NA       NA     -0.178     0.522 
##       MarketID10:AgeOfStore    -0.090            NA        3.412        NA       NA     -0.301     0.122 
##              MarketID2:Week     0.283            NA       -0.329        NA       NA     -2.059     2.625 
##              MarketID3:Week     0.271            NA       -0.398        NA       NA     -1.479     2.020 
##              MarketID4:Week     1.580            NA       -0.026        NA       NA     -0.630     3.789 
##              MarketID5:Week    -0.302            NA       -0.003        NA       NA     -2.162     1.558 
##              MarketID6:Week    -0.046            NA        0.003        NA       NA     -1.960     1.867 
##              MarketID7:Week     0.299            NA       -0.008        NA       NA     -1.578     2.176 
##              MarketID8:Week     0.240            NA        0.012        NA       NA     -1.716     2.196 
##              MarketID9:Week     1.685            NA        0.000        NA       NA     -0.415     3.785 
##             MarketID10:Week     1.449            NA        0.011        NA       NA     -0.297     3.196 
## MarketSizeMedium:AgeOfStore        NA            NA       -0.079        NA       NA         NA        NA 
##  MarketSizeSmall:AgeOfStore        NA            NA       -0.011        NA       NA         NA        NA 
##       MarketSizeMedium:Week        NA            NA        0.016        NA       NA         NA        NA 
##        MarketSizeSmall:Week        NA            NA       -0.005        NA       NA         NA        NA 
##       Promotion2:AgeOfStore    -0.121            NA        0.096        NA       NA     -0.345     0.103 
##       Promotion3:AgeOfStore     0.157            NA        0.096        NA       NA     -0.041     0.354 
## ---------------------------------------------------------------------------------------------------------
## 
## 
## - Week 
## 
## Backward Elimination: Step 6 
## 
##  Variable Week Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.957       RMSE                5.053 
## R-Squared               0.915       Coef. Var           9.499 
## Adj. R-Squared          0.908       MSE                25.533 
## Pred R-Squared          0.900       MAE                 3.891 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108795.553         33       3296.835    129.122    0.0000 
## Residual       10110.934        396         25.533                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    42.102         2.630                 16.008    0.000     36.931    47.273 
##                   MarketID2    23.673         4.296        0.300     5.511    0.000     15.228    32.119 
##                   MarketID3    50.546         3.056        1.082    16.541    0.000     44.538    56.554 
##                   MarketID4    13.187         3.622        0.189     3.641    0.000      6.066    20.308 
##                   MarketID5    16.892         3.172        0.317     5.325    0.000     10.655    23.129 
##                   MarketID6     0.125         3.270        0.002     0.038    0.970     -6.304     6.553 
##                   MarketID7    11.139         3.231        0.213     3.448    0.001      4.788    17.490 
##                   MarketID8    12.368         3.409        0.214     3.629    0.000      5.667    19.069 
##                   MarketID9    11.391         3.750        0.175     3.038    0.003      4.019    18.764 
##                  MarketID10    16.252         3.037        0.352     5.352    0.000     10.282    22.223 
##            MarketSizeMedium        NA         1.094       -0.273    -8.431    0.000         NA        NA 
##             MarketSizeSmall        NA         1.111       -0.126    -6.122    0.000         NA        NA 
##                  Promotion2    -9.223         0.202       -0.001    -0.238    0.812    -11.374    -7.073 
##                  Promotion3    -6.798         0.167        0.002     0.404    0.686     -8.982    -4.615 
##  MarketID2:MarketSizeMedium        NA         0.119        0.000    -1.324    0.186         NA        NA 
##  MarketID3:MarketSizeMedium        NA         0.167        0.000     1.436    0.152         NA        NA 
##  MarketID4:MarketSizeMedium        NA         0.147        0.000     0.019    0.985         NA        NA 
##  MarketID5:MarketSizeMedium        NA         0.142        0.003     1.279    0.202         NA        NA 
##  MarketID6:MarketSizeMedium        NA         0.142       -0.004    -1.359    0.175         NA        NA 
##  MarketID7:MarketSizeMedium        NA         0.106       -0.001    -0.403    0.687         NA        NA 
##  MarketID8:MarketSizeMedium        NA         0.178        0.003     0.968    0.333         NA        NA 
##  MarketID9:MarketSizeMedium        NA         0.108       -0.001    -0.833    0.406         NA        NA 
## MarketID10:MarketSizeMedium        NA         0.687        0.000    -0.991    0.322         NA        NA 
##   MarketID2:MarketSizeSmall        NA         0.973       -0.005    -0.409    0.683         NA        NA 
##   MarketID3:MarketSizeSmall        NA         0.566        0.000    -0.724    0.469         NA        NA 
##   MarketID4:MarketSizeSmall        NA         0.889        0.013     1.011    0.313         NA        NA 
##   MarketID5:MarketSizeSmall        NA         0.651        0.000    -1.510    0.132         NA        NA 
##   MarketID6:MarketSizeSmall        NA         0.690        0.000    -1.053    0.293         NA        NA 
##   MarketID7:MarketSizeSmall        NA         0.663        0.000    -0.576    0.565         NA        NA 
##   MarketID8:MarketSizeSmall        NA         0.720        0.000    -0.612    0.541         NA        NA 
##   MarketID9:MarketSizeSmall        NA         0.817        0.000     1.228    0.220         NA        NA 
##  MarketID10:MarketSizeSmall        NA         0.564        0.000     1.363    0.174         NA        NA 
##        MarketID1:AgeOfStore    -0.048         0.114       -0.020    -1.061    0.289     -0.446     0.350 
##        MarketID2:AgeOfStore     0.067         0.100        0.030     1.562    0.119     -0.260     0.395 
##        MarketID3:AgeOfStore    -0.158            NA        5.234        NA       NA     -0.392     0.076 
##        MarketID4:AgeOfStore     0.240            NA        8.387        NA       NA     -0.089     0.569 
##        MarketID5:AgeOfStore     0.003            NA        3.072        NA       NA     -0.287     0.292 
##        MarketID6:AgeOfStore     0.181            NA        3.482        NA       NA     -0.097     0.460 
##        MarketID7:AgeOfStore    -0.193            NA        0.024        NA       NA     -0.473     0.086 
##        MarketID8:AgeOfStore    -0.043            NA        3.018        NA       NA     -0.251     0.166 
##        MarketID9:AgeOfStore     0.172            NA        1.873        NA       NA     -0.178     0.522 
##       MarketID10:AgeOfStore    -0.090            NA        2.391        NA       NA     -0.301     0.122 
##              MarketID1:Week    -0.681            NA        0.786        NA       NA     -2.031     0.670 
##              MarketID2:Week    -0.398            NA       -0.329        NA       NA     -2.311     1.516 
##              MarketID3:Week    -0.410            NA       -0.398        NA       NA     -1.522     0.703 
##              MarketID4:Week     0.899            NA       -0.002        NA       NA     -0.850     2.647 
##              MarketID5:Week    -0.983            NA        0.004        NA       NA     -2.263     0.297 
##              MarketID6:Week    -0.727            NA       -0.008        NA       NA     -2.084     0.630 
##              MarketID7:Week    -0.382            NA        0.013        NA       NA     -1.686     0.922 
##              MarketID8:Week    -0.441            NA        0.000        NA       NA     -1.856     0.974 
##              MarketID9:Week     1.004            NA        0.008        NA       NA     -0.603     2.611 
##             MarketID10:Week     0.768            NA       -0.011        NA       NA     -0.340     1.877 
## MarketSizeMedium:AgeOfStore        NA            NA       -0.018        NA       NA         NA        NA 
##  MarketSizeSmall:AgeOfStore        NA            NA        0.043        NA       NA         NA        NA 
##       MarketSizeMedium:Week        NA            NA       -0.008        NA       NA         NA        NA 
##        MarketSizeSmall:Week        NA            NA       -0.035        NA       NA         NA        NA 
##       Promotion2:AgeOfStore    -0.121            NA       -0.134        NA       NA     -0.345     0.103 
##       Promotion3:AgeOfStore     0.157            NA       -0.146        NA       NA     -0.041     0.354 
## ---------------------------------------------------------------------------------------------------------
## 
## 
## - MarketID:Week 
## 
## Backward Elimination: Step 7 
## 
##  Variable MarketID:Week Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.956       RMSE                5.055 
## R-Squared               0.913       Coef. Var           9.502 
## Adj. R-Squared          0.908       MSE                25.550 
## Pred R-Squared          0.902       MAE                 3.902 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108609.919         26       4177.305    163.497    0.0000 
## Residual       10296.568        403         25.550                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    41.521         2.105                 19.728    0.000     37.383    45.658 
##                   MarketID2    22.405         3.542        0.284     6.325    0.000     15.442    29.369 
##                   MarketID3    49.663         2.427        1.063    20.462    0.000     44.891    54.434 
##                   MarketID4    15.217         2.922        0.218     5.207    0.000      9.472    20.962 
##                   MarketID5    16.255         2.198        0.305     7.395    0.000     11.934    20.577 
##                   MarketID6     0.030         2.188        0.001     0.014    0.989     -4.271     4.331 
##                   MarketID7    11.877         2.214        0.227     5.364    0.000      7.524    16.229 
##                   MarketID8    12.966         2.277        0.224     5.695    0.000      8.491    17.442 
##                   MarketID9    15.977         2.439        0.245     6.550    0.000     11.182    20.772 
##                  MarketID10    18.270         2.402        0.396     7.605    0.000     13.547    22.993 
##            MarketSizeMedium        NA         1.093       -0.274    -8.467    0.000         NA        NA 
##             MarketSizeSmall        NA         1.110       -0.126    -6.093    0.000         NA        NA 
##                  Promotion2    -9.257         0.202       -0.001    -0.229    0.819    -11.406    -7.108 
##                  Promotion3    -6.762         0.167        0.002     0.420    0.675     -8.944    -4.581 
##  MarketID2:MarketSizeMedium        NA         0.119        0.000    -1.323    0.187         NA        NA 
##  MarketID3:MarketSizeMedium        NA         0.167        0.000     1.421    0.156         NA        NA 
##  MarketID4:MarketSizeMedium        NA         0.146        0.000    -0.074    0.941         NA        NA 
##  MarketID5:MarketSizeMedium        NA         0.142        0.003     1.269    0.205         NA        NA 
##  MarketID6:MarketSizeMedium        NA         0.142       -0.004    -1.356    0.176         NA        NA 
##  MarketID7:MarketSizeMedium        NA         0.106       -0.001    -0.401    0.689         NA        NA 
##  MarketID8:MarketSizeMedium        NA         0.178        0.003     0.909    0.364         NA        NA 
##  MarketID9:MarketSizeMedium        NA         0.108       -0.001    -0.817    0.414         NA        NA 
## MarketID10:MarketSizeMedium        NA         0.400        0.000     0.455    0.650         NA        NA 
##   MarketID2:MarketSizeSmall        NA         0.286       -0.006    -1.570    0.117         NA        NA 
##   MarketID3:MarketSizeSmall        NA         0.657        0.000     0.471    0.638         NA        NA 
##   MarketID4:MarketSizeSmall        NA         0.114       -0.002    -1.030    0.304         NA        NA 
##   MarketID5:MarketSizeSmall        NA         0.100        0.000     1.544    0.123         NA        NA 
##   MarketID6:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID7:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID8:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID9:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##  MarketID10:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##        MarketID1:AgeOfStore    -0.046            NA        1.984        NA       NA     -0.444     0.352 
##        MarketID2:AgeOfStore     0.070            NA        2.520        NA       NA     -0.257     0.397 
##        MarketID3:AgeOfStore    -0.157            NA        3.532        NA       NA     -0.391     0.077 
##        MarketID4:AgeOfStore     0.238            NA        3.031        NA       NA     -0.091     0.566 
##        MarketID5:AgeOfStore    -0.011            NA       -2.156        NA       NA     -0.298     0.277 
##        MarketID6:AgeOfStore     0.180            NA       -1.394        NA       NA     -0.099     0.458 
##        MarketID7:AgeOfStore    -0.193            NA       -0.009        NA       NA     -0.472     0.087 
##        MarketID8:AgeOfStore    -0.042            NA        0.019        NA       NA     -0.251     0.166 
##        MarketID9:AgeOfStore     0.162            NA       -0.024        NA       NA     -0.188     0.511 
##       MarketID10:AgeOfStore    -0.088            NA        0.050        NA       NA     -0.299     0.123 
## MarketSizeMedium:AgeOfStore        NA            NA       -0.004        NA       NA         NA        NA 
##  MarketSizeSmall:AgeOfStore        NA            NA        0.045        NA       NA         NA        NA 
##        MarketSizeLarge:Week     0.182            NA       -0.015        NA       NA     -0.604     0.968 
##       MarketSizeMedium:Week    -0.448            NA       -0.004        NA       NA     -1.009     0.113 
##        MarketSizeSmall:Week     0.310            NA        0.008        NA       NA     -0.982     1.601 
##       Promotion2:AgeOfStore    -0.117            NA       -0.030        NA       NA     -0.341     0.106 
##       Promotion3:AgeOfStore     0.155            NA        0.065        NA       NA     -0.042     0.352 
## ---------------------------------------------------------------------------------------------------------
## 
## 
## - MarketSize:Week 
## 
## Backward Elimination: Step 8 
## 
##  Variable MarketSize:Week Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.955       RMSE                5.054 
## R-Squared               0.913       Coef. Var           9.501 
## Adj. R-Squared          0.908       MSE                25.543 
## Pred R-Squared          0.902       MAE                 3.940 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108535.982         23       4718.956    184.745    0.0000 
## Residual       10370.505        406         25.543                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    40.361         1.971                 20.476    0.000     36.486    44.236 
##                   MarketID2    24.307         3.040        0.308     7.996    0.000     18.331    30.283 
##                   MarketID3    51.254         2.089        1.097    24.535    0.000     47.147    55.361 
##                   MarketID4    17.142         2.344        0.246     7.315    0.000     12.535    21.749 
##                   MarketID5    16.382         2.196        0.307     7.458    0.000     12.064    20.700 
##                   MarketID6     0.089         2.187        0.002     0.041    0.967     -4.210     4.389 
##                   MarketID7    11.937         2.213        0.228     5.393    0.000      7.586    16.288 
##                   MarketID8    12.957         2.276        0.224     5.692    0.000      8.482    17.432 
##                   MarketID9    15.889         2.438        0.243     6.517    0.000     11.096    20.682 
##                  MarketID10    19.863         2.070        0.431     9.597    0.000     15.794    23.931 
##            MarketSizeMedium        NA         1.093       -0.274    -8.477    0.000         NA        NA 
##             MarketSizeSmall        NA         1.109       -0.125    -6.056    0.000         NA        NA 
##                  Promotion2    -9.266         0.202       -0.001    -0.196    0.845    -11.414    -7.117 
##                  Promotion3    -6.715         0.167        0.002     0.428    0.669     -8.895    -4.536 
##  MarketID2:MarketSizeMedium        NA         0.119        0.000    -1.338    0.182         NA        NA 
##  MarketID3:MarketSizeMedium        NA         0.167        0.000     1.396    0.164         NA        NA 
##  MarketID4:MarketSizeMedium        NA         0.146        0.000    -0.165    0.869         NA        NA 
##  MarketID5:MarketSizeMedium        NA         0.142        0.003     1.247    0.213         NA        NA 
##  MarketID6:MarketSizeMedium        NA         0.142       -0.004    -1.381    0.168         NA        NA 
##  MarketID7:MarketSizeMedium        NA         0.106       -0.001    -0.410    0.682         NA        NA 
##  MarketID8:MarketSizeMedium        NA         0.178        0.003     0.921    0.358         NA        NA 
##  MarketID9:MarketSizeMedium        NA         0.107       -0.001    -0.824    0.411         NA        NA 
## MarketID10:MarketSizeMedium        NA         0.114        0.000    -0.987    0.324         NA        NA 
##   MarketID2:MarketSizeSmall        NA         0.100        0.002     1.535    0.126         NA        NA 
##   MarketID3:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID4:MarketSizeSmall        NA            NA        0.735        NA       NA         NA        NA 
##   MarketID5:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID6:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID7:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID8:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID9:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##  MarketID10:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##        MarketID1:AgeOfStore    -0.040            NA        3.318        NA       NA     -0.437     0.358 
##        MarketID2:AgeOfStore     0.071            NA       -1.801        NA       NA     -0.256     0.399 
##        MarketID3:AgeOfStore    -0.159            NA       -1.485        NA       NA     -0.393     0.075 
##        MarketID4:AgeOfStore     0.233            NA       -0.007        NA       NA     -0.095     0.562 
##        MarketID5:AgeOfStore    -0.024            NA        0.017        NA       NA     -0.311     0.263 
##        MarketID6:AgeOfStore     0.176            NA       -0.033        NA       NA     -0.102     0.455 
##        MarketID7:AgeOfStore    -0.196            NA        0.044        NA       NA     -0.476     0.083 
##        MarketID8:AgeOfStore    -0.043            NA       -0.007        NA       NA     -0.251     0.165 
##        MarketID9:AgeOfStore     0.164            NA        0.027        NA       NA     -0.186     0.513 
##       MarketID10:AgeOfStore    -0.089            NA       -0.041        NA       NA     -0.300     0.123 
## MarketSizeMedium:AgeOfStore        NA            NA       -0.018        NA       NA         NA        NA 
##  MarketSizeSmall:AgeOfStore        NA            NA        0.041        NA       NA         NA        NA 
##       Promotion2:AgeOfStore    -0.112            NA       -0.030        NA       NA     -0.336     0.111 
##       Promotion3:AgeOfStore     0.154            NA       -0.040        NA       NA     -0.043     0.351 
## ---------------------------------------------------------------------------------------------------------
## 
## 
## - MarketID:AgeOfStore 
## 
## Backward Elimination: Step 9 
## 
##  Variable MarketID:AgeOfStore Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.955       RMSE                5.049 
## R-Squared               0.911       Coef. Var           9.492 
## Adj. R-Squared          0.908       MSE                25.492 
## Pred R-Squared          0.904       MAE                 3.975 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108378.252         16       6773.641    265.715    0.0000 
## Residual       10528.234        413         25.492                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    40.142         1.126                 35.666    0.000     37.930    42.355 
##                   MarketID2    23.286         2.027        0.295    11.488    0.000     19.302    27.271 
##                   MarketID3    51.166         1.267        1.095    40.393    0.000     48.676    53.656 
##                   MarketID4    17.982         1.561        0.258    11.517    0.000     14.913    21.052 
##                   MarketID5    16.311         1.101        0.306    14.815    0.000     14.146    18.475 
##                   MarketID6     1.833         1.087        0.034     1.686    0.092     -0.304     3.969 
##                   MarketID7    10.631         1.072        0.203     9.914    0.000      8.523    12.739 
##                   MarketID8    12.690         1.159        0.219    10.947    0.000     10.411    14.969 
##                   MarketID9    17.443         1.222        0.267    14.269    0.000     15.040    19.846 
##                  MarketID10    20.343         1.220        0.441    16.669    0.000     17.944    22.742 
##            MarketSizeMedium        NA         0.999       -0.278    -9.411    0.000         NA        NA 
##             MarketSizeSmall        NA         1.073       -0.123    -6.153    0.000         NA        NA 
##                  Promotion2    -9.405         0.083       -0.004    -1.781    0.076    -11.369    -7.441 
##                  Promotion3    -6.603         0.077       -0.001    -0.353    0.724     -8.712    -4.493 
##  MarketID2:MarketSizeMedium        NA         0.119        0.000     1.164    0.245         NA        NA 
##  MarketID3:MarketSizeMedium        NA         0.094        0.000    -0.693    0.489         NA        NA 
##  MarketID4:MarketSizeMedium        NA         0.094        0.000     1.921    0.055         NA        NA 
##  MarketID5:MarketSizeMedium        NA            NA        0.437        NA       NA         NA        NA 
##  MarketID6:MarketSizeMedium        NA            NA        0.960        NA       NA         NA        NA 
##  MarketID7:MarketSizeMedium        NA            NA        0.344        NA       NA         NA        NA 
##  MarketID8:MarketSizeMedium        NA            NA        0.282        NA       NA         NA        NA 
##  MarketID9:MarketSizeMedium        NA            NA        0.028        NA       NA         NA        NA 
## MarketID10:MarketSizeMedium        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID2:MarketSizeSmall        NA            NA        0.161        NA       NA         NA        NA 
##   MarketID3:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID4:MarketSizeSmall        NA            NA        0.292        NA       NA         NA        NA 
##   MarketID5:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID6:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID7:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID8:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##   MarketID9:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##  MarketID10:MarketSizeSmall        NA            NA        0.000        NA       NA         NA        NA 
##  MarketSizeLarge:AgeOfStore    -0.148            NA        0.052        NA       NA     -0.311     0.015 
## MarketSizeMedium:AgeOfStore    -0.027            NA        9.566        NA       NA     -0.179     0.125 
##  MarketSizeSmall:AgeOfStore     0.139            NA       12.845        NA       NA     -0.096     0.374 
##       Promotion2:AgeOfStore    -0.065            NA        6.079        NA       NA     -0.250     0.119 
##       Promotion3:AgeOfStore     0.181            NA        5.808        NA       NA     -0.004     0.365 
## ---------------------------------------------------------------------------------------------------------
## 
## 
## - MarketSize:AgeOfStore 
## 
## Backward Elimination: Step 10 
## 
##  Variable MarketSize:AgeOfStore Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.954       RMSE                5.069 
## R-Squared               0.910       Coef. Var           9.530 
## Adj. R-Squared          0.907       MSE                25.696 
## Pred R-Squared          0.904       MAE                 4.005 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108242.481         14       7731.606    300.883    0.0000 
## Residual       10664.006        415         25.696                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                             
## ----------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta       t        Sig       lower     upper 
## ----------------------------------------------------------------------------------------------------------
##                 (Intercept)    40.573         1.061                  38.255    0.000     38.488    42.658 
##                   MarketID2    25.611         1.433        0.324     17.870    0.000     22.794    28.428 
##                   MarketID3    50.165         1.032        1.074     48.615    0.000     48.137    52.193 
##                   MarketID4    19.305         1.273        0.277     15.166    0.000     16.803    21.807 
##                   MarketID5    16.278         1.104        0.305     14.748    0.000     14.108    18.448 
##                   MarketID6     1.768         1.091        0.033      1.621    0.106     -0.376     3.912 
##                   MarketID7    10.650         1.076        0.203      9.894    0.000      8.534    12.766 
##                   MarketID8    12.701         1.161        0.219     10.943    0.000     10.420    14.982 
##                   MarketID9    17.397         1.226        0.267     14.185    0.000     14.987    19.808 
##                  MarketID10    19.410         1.012        0.421     19.179    0.000     17.421    21.400 
##            MarketSizeMedium        NA         0.970       -0.294    -10.259    0.000         NA        NA 
##             MarketSizeSmall        NA         1.063       -0.130     -6.559    0.000         NA        NA 
##                  Promotion2    -9.949         0.066       -0.002     -0.952    0.342    -11.855    -8.042 
##                  Promotion3    -6.971         0.062       -0.002     -1.268    0.205     -9.060    -4.882 
##  MarketID2:MarketSizeMedium        NA         0.067        0.000      2.179    0.030         NA        NA 
##  MarketID3:MarketSizeMedium        NA            NA        0.000         NA       NA         NA        NA 
##  MarketID4:MarketSizeMedium        NA            NA        0.000         NA       NA         NA        NA 
##  MarketID5:MarketSizeMedium        NA            NA        0.362         NA       NA         NA        NA 
##  MarketID6:MarketSizeMedium        NA            NA        0.305         NA       NA         NA        NA 
##  MarketID7:MarketSizeMedium        NA            NA        0.034         NA       NA         NA        NA 
##  MarketID8:MarketSizeMedium        NA            NA        0.184         NA       NA         NA        NA 
##  MarketID9:MarketSizeMedium        NA            NA        0.195         NA       NA         NA        NA 
## MarketID10:MarketSizeMedium        NA            NA        0.000         NA       NA         NA        NA 
##   MarketID2:MarketSizeSmall        NA            NA        0.246         NA       NA         NA        NA 
##   MarketID3:MarketSizeSmall        NA            NA        0.000         NA       NA         NA        NA 
##   MarketID4:MarketSizeSmall        NA            NA       -0.100         NA       NA         NA        NA 
##   MarketID5:MarketSizeSmall        NA            NA        0.000         NA       NA         NA        NA 
##   MarketID6:MarketSizeSmall        NA            NA        0.000         NA       NA         NA        NA 
##   MarketID7:MarketSizeSmall        NA            NA        0.000         NA       NA         NA        NA 
##   MarketID8:MarketSizeSmall        NA            NA        0.000         NA       NA         NA        NA 
##   MarketID9:MarketSizeSmall        NA            NA        0.000         NA       NA         NA        NA 
##  MarketID10:MarketSizeSmall        NA            NA        0.000         NA       NA         NA        NA 
##       Promotion1:AgeOfStore    -0.063            NA        5.412         NA       NA     -0.193     0.067 
##       Promotion2:AgeOfStore    -0.079            NA        0.598         NA       NA     -0.202     0.043 
##       Promotion3:AgeOfStore     0.145            NA        3.792         NA       NA      0.014     0.276 
## ----------------------------------------------------------------------------------------------------------
## 
## 
## - AgeOfStore:Promotion 
## 
## Backward Elimination: Step 11 
## 
##  Variable AgeOfStore:Promotion Removed 
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.953       RMSE                5.096 
## R-Squared               0.909       Coef. Var           9.579 
## Adj. R-Squared          0.906       MSE                25.966 
## Pred R-Squared          0.903       MAE                 4.044 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108052.847         11       9822.986    378.307    0.0000 
## Residual       10853.640        418         25.966                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                             Parameter Estimates                                             
## -----------------------------------------------------------------------------------------------------------
##                       model       Beta    Std. Error    Std. Beta       t        Sig       lower     upper 
## -----------------------------------------------------------------------------------------------------------
##                 (Intercept)     39.939         0.851                  46.950    0.000     38.267    41.611 
##                   MarketID2     25.718         1.428        0.326     18.008    0.000     22.911    28.525 
##                   MarketID3     50.095         1.025        1.072     48.857    0.000     48.080    52.111 
##                   MarketID4     19.350         1.273        0.277     15.195    0.000     16.847    21.853 
##                   MarketID5     16.185         1.095        0.304     14.782    0.000     14.033    18.337 
##                   MarketID6      2.029         1.083        0.038      1.875    0.062     -0.098     4.157 
##                   MarketID7     10.598         1.082        0.203      9.798    0.000      8.472    12.724 
##                   MarketID8     13.156         1.143        0.227     11.513    0.000     10.910    15.402 
##                   MarketID9     17.626         1.226        0.270     14.374    0.000     15.216    20.037 
##                  MarketID10     19.523         1.007        0.423     19.392    0.000     17.544    21.502 
##            MarketSizeMedium         NA         0.619       -0.297    -16.217    0.000         NA        NA 
##             MarketSizeSmall         NA         0.635       -0.093     -7.916    0.000         NA        NA 
##                  Promotion2    -10.039            NA        0.739         NA       NA    -11.255    -8.822 
##                  Promotion3     -5.027            NA        1.412         NA       NA     -6.275    -3.779 
##  MarketID2:MarketSizeMedium         NA            NA        0.000         NA       NA         NA        NA 
##  MarketID3:MarketSizeMedium         NA            NA        0.000         NA       NA         NA        NA 
##  MarketID4:MarketSizeMedium         NA            NA        0.000         NA       NA         NA        NA 
##  MarketID5:MarketSizeMedium         NA            NA        0.199         NA       NA         NA        NA 
##  MarketID6:MarketSizeMedium         NA            NA        0.247         NA       NA         NA        NA 
##  MarketID7:MarketSizeMedium         NA            NA        0.337         NA       NA         NA        NA 
##  MarketID8:MarketSizeMedium         NA            NA        0.337         NA       NA         NA        NA 
##  MarketID9:MarketSizeMedium         NA            NA       -0.154         NA       NA         NA        NA 
## MarketID10:MarketSizeMedium         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID2:MarketSizeSmall         NA            NA        0.326         NA       NA         NA        NA 
##   MarketID3:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID4:MarketSizeSmall         NA            NA        0.277         NA       NA         NA        NA 
##   MarketID5:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID6:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID7:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID8:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID9:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##  MarketID10:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
## -----------------------------------------------------------------------------------------------------------
## 
## 
## 
## No more variables satisfy the condition of p value = 0.05
## 
## 
## Variables Removed: 
## 
## - AgeOfStore 
## - MarketID:Promotion 
## - AgeOfStore:Week 
## - Promotion:Week 
## - MarketSize:Promotion 
## - Week 
## - MarketID:Week 
## - MarketSize:Week 
## - MarketID:AgeOfStore 
## - MarketSize:AgeOfStore 
## - AgeOfStore:Promotion 
## 
## 
## Final Model Output 
## ------------------
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.953       RMSE                5.096 
## R-Squared               0.909       Coef. Var           9.579 
## Adj. R-Squared          0.906       MSE                25.966 
## Pred R-Squared          0.903       MAE                 4.044 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108052.847         11       9822.986    378.307    0.0000 
## Residual       10853.640        418         25.966                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                             Parameter Estimates                                             
## -----------------------------------------------------------------------------------------------------------
##                       model       Beta    Std. Error    Std. Beta       t        Sig       lower     upper 
## -----------------------------------------------------------------------------------------------------------
##                 (Intercept)     39.939         0.851                  46.950    0.000     38.267    41.611 
##                   MarketID2     25.718         1.428        0.326     18.008    0.000     22.911    28.525 
##                   MarketID3     50.095         1.025        1.072     48.857    0.000     48.080    52.111 
##                   MarketID4     19.350         1.273        0.277     15.195    0.000     16.847    21.853 
##                   MarketID5     16.185         1.095        0.304     14.782    0.000     14.033    18.337 
##                   MarketID6      2.029         1.083        0.038      1.875    0.062     -0.098     4.157 
##                   MarketID7     10.598         1.082        0.203      9.798    0.000      8.472    12.724 
##                   MarketID8     13.156         1.143        0.227     11.513    0.000     10.910    15.402 
##                   MarketID9     17.626         1.226        0.270     14.374    0.000     15.216    20.037 
##                  MarketID10     19.523         1.007        0.423     19.392    0.000     17.544    21.502 
##            MarketSizeMedium         NA         0.619       -0.297    -16.217    0.000         NA        NA 
##             MarketSizeSmall         NA         0.635       -0.093     -7.916    0.000         NA        NA 
##                  Promotion2    -10.039            NA        0.739         NA       NA    -11.255    -8.822 
##                  Promotion3     -5.027            NA        1.412         NA       NA     -6.275    -3.779 
##  MarketID2:MarketSizeMedium         NA            NA        0.000         NA       NA         NA        NA 
##  MarketID3:MarketSizeMedium         NA            NA        0.000         NA       NA         NA        NA 
##  MarketID4:MarketSizeMedium         NA            NA        0.000         NA       NA         NA        NA 
##  MarketID5:MarketSizeMedium         NA            NA        0.199         NA       NA         NA        NA 
##  MarketID6:MarketSizeMedium         NA            NA        0.247         NA       NA         NA        NA 
##  MarketID7:MarketSizeMedium         NA            NA        0.337         NA       NA         NA        NA 
##  MarketID8:MarketSizeMedium         NA            NA        0.337         NA       NA         NA        NA 
##  MarketID9:MarketSizeMedium         NA            NA       -0.154         NA       NA         NA        NA 
## MarketID10:MarketSizeMedium         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID2:MarketSizeSmall         NA            NA        0.326         NA       NA         NA        NA 
##   MarketID3:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID4:MarketSizeSmall         NA            NA        0.277         NA       NA         NA        NA 
##   MarketID5:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID6:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID7:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID8:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##   MarketID9:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
##  MarketID10:MarketSizeSmall         NA            NA        0.000         NA       NA         NA        NA 
## -----------------------------------------------------------------------------------------------------------
## 
## Call:
## lm(formula = paste(response, "~", paste(preds, collapse = " + ")), 
##     data = l)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -14.5894  -3.3428  -0.1003   3.2096  14.2140 
## 
## Coefficients: (20 not defined because of singularities)
##                             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                  39.9386     0.8507  46.950  < 2e-16 ***
## MarketID2                    25.7183     1.4281  18.008  < 2e-16 ***
## MarketID3                    50.0952     1.0253  48.857  < 2e-16 ***
## MarketID4                    19.3497     1.2734  15.195  < 2e-16 ***
## MarketID5                    16.1848     1.0949  14.782  < 2e-16 ***
## MarketID6                     2.0295     1.0825   1.875   0.0615 .  
## MarketID7                    10.5980     1.0816   9.798  < 2e-16 ***
## MarketID8                    13.1561     1.1427  11.513  < 2e-16 ***
## MarketID9                    17.6263     1.2262  14.374  < 2e-16 ***
## MarketID10                   19.5234     1.0068  19.392  < 2e-16 ***
## MarketSizeMedium                  NA         NA      NA       NA    
## MarketSizeSmall                   NA         NA      NA       NA    
## Promotion2                  -10.0387     0.6190 -16.217  < 2e-16 ***
## Promotion3                   -5.0267     0.6350  -7.916 2.23e-14 ***
## MarketID2:MarketSizeMedium        NA         NA      NA       NA    
## MarketID3:MarketSizeMedium        NA         NA      NA       NA    
## MarketID4:MarketSizeMedium        NA         NA      NA       NA    
## MarketID5:MarketSizeMedium        NA         NA      NA       NA    
## MarketID6:MarketSizeMedium        NA         NA      NA       NA    
## MarketID7:MarketSizeMedium        NA         NA      NA       NA    
## MarketID8:MarketSizeMedium        NA         NA      NA       NA    
## MarketID9:MarketSizeMedium        NA         NA      NA       NA    
## MarketID10:MarketSizeMedium       NA         NA      NA       NA    
## MarketID2:MarketSizeSmall         NA         NA      NA       NA    
## MarketID3:MarketSizeSmall         NA         NA      NA       NA    
## MarketID4:MarketSizeSmall         NA         NA      NA       NA    
## MarketID5:MarketSizeSmall         NA         NA      NA       NA    
## MarketID6:MarketSizeSmall         NA         NA      NA       NA    
## MarketID7:MarketSizeSmall         NA         NA      NA       NA    
## MarketID8:MarketSizeSmall         NA         NA      NA       NA    
## MarketID9:MarketSizeSmall         NA         NA      NA       NA    
## MarketID10:MarketSizeSmall        NA         NA      NA       NA    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 5.096 on 418 degrees of freedom
## Multiple R-squared:  0.9087, Adjusted R-squared:  0.9063 
## F-statistic: 378.3 on 11 and 418 DF,  p-value: < 2.2e-16
## Backward Elimination Method 
## ---------------------------
## 
## Candidate Terms: 
## 
## 1 . MarketID 
## 2 . MarketSize 
## 3 . AgeOfStore 
## 4 . Promotion 
## 5 . Week 
## 6 . MarketID:MarketSize 
## 7 . MarketID:AgeOfStore 
## 8 . MarketID:Promotion 
## 9 . MarketID:Week 
## 10 . MarketSize:AgeOfStore 
## 11 . MarketSize:Promotion 
## 12 . MarketSize:Week 
## 13 . AgeOfStore:Promotion 
## 14 . AgeOfStore:Week 
## 15 . Promotion:Week 
## 
##  Step 0: AIC = 2730.493 
##  SalesInThousands ~ MarketID + MarketSize + AgeOfStore + Promotion + Week + MarketID:MarketSize + MarketID:AgeOfStore + MarketID:Promotion + MarketID:Week + MarketSize:AgeOfStore + MarketSize:Promotion + MarketSize:Week + AgeOfStore:Promotion + AgeOfStore:Week + Promotion:Week 
## 
## -------------------------------------------------------------------------------------
## Variable                 DF      AIC       Sum Sq        RSS       R-Sq     Adj. R-Sq 
## -------------------------------------------------------------------------------------
## MarketID                 1     2730.493      0.000     9751.669    0.918        0.906 
## Week                     1     2730.493      0.000     9751.669    0.918        0.906 
## MarketSize               1     2730.493      0.000     9751.669    0.918        0.906 
## MarketID:MarketSize      1     2694.493      0.000     9751.669    0.918        0.906 
## MarketSize:AgeOfStore    1     2726.493      0.000     9751.669    0.918        0.906 
## MarketSize:Promotion     1     2722.493      0.000     9751.669    0.918        0.906 
## MarketSize:Week          1     2726.493      0.000     9751.669    0.918        0.906 
## Promotion                1     2730.493      0.000     9751.669    0.918        0.906 
## AgeOfStore               1     2730.493      0.000     9751.669    0.918        0.906 
## AgeOfStore:Week          1     2728.706      4.840     9756.508    0.918        0.907 
## Promotion:Week           1     2727.837     30.541     9782.209    0.918        0.907 
## AgeOfStore:Promotion     1     2730.615     93.940     9845.608    0.917        0.906 
## MarketID:Week            1     2721.283    201.406     9953.075    0.916        0.906 
## MarketID:AgeOfStore      1     2722.235    223.468     9975.137    0.916        0.906 
## MarketID:Promotion       1     2705.325    248.782    10000.451    0.916        0.907 
## -------------------------------------------------------------------------------------
## 
## 
## Variables Removed: 
## 
## - MarketID:MarketSize 
## 
## 
##   Step 1 : AIC = 2694.493 
##  SalesInThousands ~ MarketID + MarketSize + AgeOfStore + Promotion + Week + MarketID:AgeOfStore + MarketID:Promotion + MarketID:Week + MarketSize:AgeOfStore + MarketSize:Promotion + MarketSize:Week + AgeOfStore:Promotion + AgeOfStore:Week + Promotion:Week 
## 
## --------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq        RSS       R-Sq     Adj. R-Sq 
## --------------------------------------------------------------------------------------
## Week                     1     2694.493       0.000     9751.669    0.918        0.906 
## MarketSize               1     2690.493       0.000     9751.669    0.918        0.906 
## MarketSize:AgeOfStore    1     2690.493       0.000     9751.669    0.918        0.906 
## MarketSize:Promotion     1     2686.493       0.000     9751.669    0.918        0.906 
## MarketSize:Week          1     2690.493       0.000     9751.669    0.918        0.906 
## Promotion                1     2694.493       0.000     9751.669    0.918        0.906 
## AgeOfStore               1     2694.493       0.000     9751.669    0.918        0.906 
## AgeOfStore:Week          1     2692.706       4.840     9756.508    0.918        0.907 
## Promotion:Week           1     2691.837      30.541     9782.209    0.918        0.907 
## AgeOfStore:Promotion     1     2694.615      93.940     9845.608    0.917        0.906 
## MarketID:Week            1     2685.283     201.406     9953.075    0.916        0.906 
## MarketID:AgeOfStore      1     2686.235     223.468     9975.137    0.916        0.906 
## MarketID:Promotion       1     2669.325     248.782    10000.451    0.916        0.907 
## MarketID                 1     2845.154    4683.594    14435.263    0.879        0.864 
## --------------------------------------------------------------------------------------
## 
## - MarketID:Promotion 
## 
## 
##   Step 2 : AIC = 2669.325 
##  SalesInThousands ~ MarketID + MarketSize + AgeOfStore + Promotion + Week + MarketID:AgeOfStore + MarketID:Week + MarketSize:AgeOfStore + MarketSize:Promotion + MarketSize:Week + AgeOfStore:Promotion + AgeOfStore:Week + Promotion:Week 
## 
## --------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq        RSS       R-Sq     Adj. R-Sq 
## --------------------------------------------------------------------------------------
## MarketSize               1     2665.325       0.000    10000.451    0.916        0.907 
## Week                     1     2669.325       0.000    10000.451    0.916        0.907 
## MarketSize:AgeOfStore    1     2665.325       0.000    10000.451    0.916        0.907 
## MarketSize:Week          1     2665.325       0.000    10000.451    0.916        0.907 
## AgeOfStore               1     2669.325       0.000    10000.451    0.916        0.907 
## Promotion                1     2669.325       0.000    10000.451    0.916        0.907 
## AgeOfStore:Week          1     2667.486       3.734    10004.185    0.916        0.907 
## Promotion:Week           1     2666.415      25.376    10025.827    0.916        0.907 
## MarketSize:Promotion     1     2664.719      79.238    10079.689    0.915        0.907 
## AgeOfStore:Promotion     1     2672.014     156.784    10157.235    0.915        0.906 
## MarketID:AgeOfStore      1     2658.066     158.005    10158.456    0.915        0.907 
## MarketID:Week            1     2659.195     184.712    10185.163    0.914        0.907 
## MarketID                 1     2853.838    6015.594    16016.045    0.865        0.854 
## --------------------------------------------------------------------------------------
## 
## - MarketID:AgeOfStore 
## 
## 
##   Step 3 : AIC = 2658.066 
##  SalesInThousands ~ MarketID + MarketSize + AgeOfStore + Promotion + Week + MarketID:Week + MarketSize:AgeOfStore + MarketSize:Promotion + MarketSize:Week + AgeOfStore:Promotion + AgeOfStore:Week + Promotion:Week 
## 
## --------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq        RSS       R-Sq     Adj. R-Sq 
## --------------------------------------------------------------------------------------
## MarketSize               1     2654.066       0.000    10158.456    0.915        0.907 
## Week                     1     2658.066       0.000    10158.456    0.915        0.907 
## MarketSize:Week          1     2654.066       0.000    10158.456    0.915        0.907 
## Promotion                1     2658.066       0.000    10158.456    0.915        0.907 
## AgeOfStore               1     2658.066       0.000    10158.456    0.915        0.907 
## AgeOfStore:Week          1     2656.287       5.228    10163.684    0.915        0.908 
## Promotion:Week           1     2655.177      26.280    10184.736    0.914        0.908 
## MarketSize:Promotion     1     2653.382      78.638    10237.094    0.914        0.908 
## MarketSize:AgeOfStore    1     2659.287     124.094    10282.551    0.914        0.907 
## MarketID:Week            1     2647.731     182.704    10341.161    0.913        0.907 
## AgeOfStore:Promotion     1     2662.306     196.543    10354.999    0.913        0.906 
## MarketID                 1     2874.597    7368.286    17526.742    0.853        0.843 
## --------------------------------------------------------------------------------------
## 
## - MarketID:Week 
## 
## 
##   Step 4 : AIC = 2647.731 
##  SalesInThousands ~ MarketID + MarketSize + AgeOfStore + Promotion + Week + MarketSize:AgeOfStore + MarketSize:Promotion + MarketSize:Week + AgeOfStore:Promotion + AgeOfStore:Week + Promotion:Week 
## 
## ---------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq         RSS       R-Sq     Adj. R-Sq 
## ---------------------------------------------------------------------------------------
## MarketSize               1     2643.731        0.000    10341.161    0.913        0.907 
## Week                     1     2647.731        0.000    10341.161    0.913        0.907 
## AgeOfStore               1     2647.731        0.000    10341.161    0.913        0.907 
## Promotion                1     2647.731        0.000    10341.161    0.913        0.907 
## AgeOfStore:Week          1     2645.774        1.025    10342.186    0.913        0.908 
## Promotion:Week           1     2645.208       35.579    10376.739    0.913        0.908 
## MarketSize:Week          1     2646.198       59.507    10400.667    0.913        0.907 
## MarketSize:Promotion     1     2642.776       73.481    10414.641    0.912        0.908 
## MarketSize:AgeOfStore    1     2648.983      127.089    10468.250    0.912        0.907 
## AgeOfStore:Promotion     1     2651.785      195.514    10536.675    0.911        0.906 
## MarketID                 1     3277.325    36285.153    46626.314    0.608        0.590 
## ---------------------------------------------------------------------------------------
## 
## - MarketSize:Promotion 
## 
## 
##   Step 5 : AIC = 2642.776 
##  SalesInThousands ~ MarketID + MarketSize + AgeOfStore + Promotion + Week + MarketSize:AgeOfStore + MarketSize:Week + AgeOfStore:Promotion + AgeOfStore:Week + Promotion:Week 
## 
## ---------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq         RSS       R-Sq     Adj. R-Sq 
## ---------------------------------------------------------------------------------------
## MarketSize               1     2638.776        0.000    10414.641    0.912        0.908 
## Week                     1     2642.776        0.000    10414.641    0.912        0.908 
## AgeOfStore               1     2642.776        0.000    10414.641    0.912        0.908 
## AgeOfStore:Week          1     2640.804        0.684    10415.325    0.912        0.908 
## Promotion:Week           1     2640.320       37.459    10452.101    0.912        0.908 
## MarketSize:Week          1     2641.040       54.994    10469.636    0.912        0.908 
## MarketSize:AgeOfStore    1     2644.225      132.812    10547.454    0.911        0.907 
## AgeOfStore:Promotion     1     2647.039      202.069    10616.710    0.911        0.906 
## Promotion                1     2662.786      598.077    11012.718    0.907        0.903 
## MarketID                 1     3297.090    39321.665    49736.307    0.582        0.567 
## ---------------------------------------------------------------------------------------
## 
## - MarketSize 
## 
## 
##   Step 6 : AIC = 2638.776 
##  SalesInThousands ~ MarketID + AgeOfStore + Promotion + Week + MarketSize:AgeOfStore + MarketSize:Week + AgeOfStore:Promotion + AgeOfStore:Week + Promotion:Week 
## 
## ---------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq         RSS       R-Sq     Adj. R-Sq 
## ---------------------------------------------------------------------------------------
## Week                     1     2638.776        0.000    10414.641    0.912        0.908 
## AgeOfStore               1     2638.776        0.000    10414.641    0.912        0.908 
## AgeOfStore:Week          1     2636.804        0.684    10415.325    0.912        0.908 
## Promotion:Week           1     2636.320       37.459    10452.101    0.912        0.908 
## MarketSize:Week          1     2637.040       54.994    10469.636    0.912        0.908 
## MarketSize:AgeOfStore    1     2640.225      132.812    10547.454    0.911        0.907 
## AgeOfStore:Promotion     1     2643.039      202.069    10616.710    0.911        0.906 
## Promotion                1     2658.786      598.077    11012.718    0.907        0.903 
## MarketID                 1     3346.602    45912.776    56327.417    0.526        0.511 
## ---------------------------------------------------------------------------------------
## 
## - Promotion:Week 
## 
## 
##   Step 7 : AIC = 2636.32 
##  SalesInThousands ~ MarketID + AgeOfStore + Promotion + Week + MarketSize:AgeOfStore + MarketSize:Week + AgeOfStore:Promotion + AgeOfStore:Week 
## 
## ---------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq         RSS       R-Sq     Adj. R-Sq 
## ---------------------------------------------------------------------------------------
## Week                     1     2636.320        0.000    10452.101    0.912        0.908 
## AgeOfStore               1     2636.320        0.000    10452.101    0.912        0.908 
## AgeOfStore:Week          1     2634.332        0.301    10452.401    0.912        0.908 
## MarketSize:Week          1     2634.754       59.341    10511.441    0.912        0.908 
## MarketSize:AgeOfStore    1     2637.847      135.233    10587.334    0.911        0.907 
## AgeOfStore:Promotion     1     2640.406      198.423    10650.523    0.910        0.907 
## Promotion                1     2718.906     2331.554    12783.655    0.892        0.888 
## MarketID                 1     3343.072    45936.871    56388.971    0.526        0.513 
## ---------------------------------------------------------------------------------------
## 
## - AgeOfStore:Week 
## 
## 
##   Step 8 : AIC = 2634.332 
##  SalesInThousands ~ MarketID + AgeOfStore + Promotion + Week + MarketSize:AgeOfStore + MarketSize:Week + AgeOfStore:Promotion 
## 
## ---------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq         RSS       R-Sq     Adj. R-Sq 
## ---------------------------------------------------------------------------------------
## Week                     1     2634.332        0.000    10452.401    0.912        0.908 
## AgeOfStore               1     2634.332        0.000    10452.401    0.912        0.908 
## MarketSize:Week          1     2632.755       59.067    10511.468    0.912        0.908 
## MarketSize:AgeOfStore    1     2635.881      135.767    10588.168    0.911        0.907 
## AgeOfStore:Promotion     1     2638.434      198.812    10651.214    0.910        0.907 
## Promotion                1     2717.043     2335.311    12787.712    0.892        0.888 
## MarketID                 1     3342.293    46096.871    56549.273    0.524        0.513 
## ---------------------------------------------------------------------------------------
## 
## - MarketSize:Week 
## 
## 
##   Step 9 : AIC = 2632.755 
##  SalesInThousands ~ MarketID + AgeOfStore + Promotion + Week + MarketSize:AgeOfStore + AgeOfStore:Promotion 
## 
## ---------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq         RSS       R-Sq     Adj. R-Sq 
## ---------------------------------------------------------------------------------------
## AgeOfStore               1     2632.755        0.000    10511.468    0.912        0.908 
## Week                     1     2631.440       16.766    10528.234    0.911        0.908 
## MarketSize:AgeOfStore    1     2634.263      135.509    10646.977    0.910        0.907 
## AgeOfStore:Promotion     1     2636.753      197.337    10708.805    0.910        0.907 
## Promotion                1     2714.715     2326.060    12837.528    0.892        0.888 
## MarketID                 1     3428.028    59160.616    69672.084    0.414        0.403 
## ---------------------------------------------------------------------------------------
## 
## - Week 
## 
## 
##   Step 10 : AIC = 2631.44 
##  SalesInThousands ~ MarketID + AgeOfStore + Promotion + MarketSize:AgeOfStore + AgeOfStore:Promotion 
## 
## ---------------------------------------------------------------------------------------
## Variable                 DF      AIC        Sum Sq         RSS       R-Sq     Adj. R-Sq 
## ---------------------------------------------------------------------------------------
## AgeOfStore               1     2631.440        0.000    10528.234    0.911        0.908 
## MarketSize:AgeOfStore    1     2632.950      135.772    10664.006    0.910        0.907 
## AgeOfStore:Promotion     1     2635.345      195.324    10723.558    0.910        0.907 
## Promotion                1     2713.173     2322.989    12851.223    0.892        0.888 
## MarketID                 1     3426.029    59143.949    69672.184    0.414        0.404 
## ---------------------------------------------------------------------------------------
## 
## 
## No more variables to be removed.
## 
## Variables Removed: 
## 
## - MarketID:MarketSize 
## - MarketID:Promotion 
## - MarketID:AgeOfStore 
## - MarketID:Week 
## - MarketSize:Promotion 
## - MarketSize 
## - Promotion:Week 
## - AgeOfStore:Week 
## - MarketSize:Week 
## - Week 
## 
## 
## Final Model Output 
## ------------------
## 
##                         Model Summary                          
## --------------------------------------------------------------
## R                       0.955       RMSE                5.049 
## R-Squared               0.911       Coef. Var           9.492 
## Adj. R-Squared          0.908       MSE                25.492 
## Pred R-Squared          0.904       MAE                 3.975 
## --------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
## 
##                                  ANOVA                                   
## ------------------------------------------------------------------------
##                   Sum of                                                
##                  Squares         DF    Mean Square       F         Sig. 
## ------------------------------------------------------------------------
## Regression    108378.252         16       6773.641    265.715    0.0000 
## Residual       10528.234        413         25.492                      
## Total         118906.487        429                                     
## ------------------------------------------------------------------------
## 
##                                            Parameter Estimates                                            
## ---------------------------------------------------------------------------------------------------------
##                       model      Beta    Std. Error    Std. Beta      t        Sig       lower     upper 
## ---------------------------------------------------------------------------------------------------------
##                 (Intercept)    40.142         1.126                 35.666    0.000     37.930    42.355 
##                   MarketID2    23.286         2.027        0.295    11.488    0.000     19.302    27.271 
##                   MarketID3    51.166         1.267        1.095    40.393    0.000     48.676    53.656 
##                   MarketID4    17.982         1.561        0.258    11.517    0.000     14.913    21.052 
##                   MarketID5    16.311         1.101        0.306    14.815    0.000     14.146    18.475 
##                   MarketID6     1.833         1.087        0.034     1.686    0.092     -0.304     3.969 
##                   MarketID7    10.631         1.072        0.203     9.914    0.000      8.523    12.739 
##                   MarketID8    12.690         1.159        0.219    10.947    0.000     10.411    14.969 
##                   MarketID9    17.443         1.222        0.267    14.269    0.000     15.040    19.846 
##                  MarketID10    20.343         1.220        0.441    16.669    0.000     17.944    22.742 
##                  AgeOfStore    -0.148         0.083       -0.060    -1.781    0.076     -0.311     0.015 
##                  Promotion2    -9.405         0.999       -0.270    -9.411    0.000    -11.369    -7.441 
##                  Promotion3    -6.603         1.073       -0.186    -6.153    0.000     -8.712    -4.493 
## AgeOfStore:MarketSizeMedium     0.120         0.089        0.049     1.354    0.177     -0.054     0.295 
##  AgeOfStore:MarketSizeSmall     0.287         0.125        0.072     2.295    0.022      0.041     0.532 
##       AgeOfStore:Promotion2    -0.065         0.094       -0.022    -0.693    0.489     -0.250     0.119 
##       AgeOfStore:Promotion3     0.181         0.094        0.064     1.921    0.055     -0.004     0.365 
## ---------------------------------------------------------------------------------------------------------
## 
## Call:
## lm(formula = paste(response, "~", paste(preds, collapse = " + ")), 
##     data = l)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -14.7685  -3.2042  -0.1668   3.3501  15.2276 
## 
## Coefficients:
##                             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                 40.14225    1.12551  35.666  < 2e-16 ***
## MarketID2                   23.28624    2.02700  11.488  < 2e-16 ***
## MarketID3                   51.16590    1.26670  40.393  < 2e-16 ***
## MarketID4                   17.98249    1.56133  11.517  < 2e-16 ***
## MarketID5                   16.31058    1.10097  14.815  < 2e-16 ***
## MarketID6                    1.83287    1.08688   1.686   0.0925 .  
## MarketID7                   10.63137    1.07240   9.914  < 2e-16 ***
## MarketID8                   12.68999    1.15922  10.947  < 2e-16 ***
## MarketID9                   17.44284    1.22247  14.269  < 2e-16 ***
## MarketID10                  20.34276    1.22037  16.669  < 2e-16 ***
## AgeOfStore                  -0.14774    0.08294  -1.781   0.0756 .  
## Promotion2                  -9.40500    0.99936  -9.411  < 2e-16 ***
## Promotion3                  -6.60275    1.07312  -6.153  1.8e-09 ***
## AgeOfStore:MarketSizeMedium  0.12044    0.08898   1.354   0.1766    
## AgeOfStore:MarketSizeSmall   0.28683    0.12498   2.295   0.0222 *  
## AgeOfStore:Promotion2       -0.06502    0.09386  -0.693   0.4889    
## AgeOfStore:Promotion3        0.18061    0.09403   1.921   0.0555 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 5.049 on 413 degrees of freedom
## Multiple R-squared:  0.9115, Adjusted R-squared:  0.908 
## F-statistic: 265.7 on 16 and 413 DF,  p-value: < 2.2e-16

Accuracy of the Model:

validationlm$predicted <- predict.lm(fit2, validationlm)

mean_SalesInThousands_val <- mean(validationlm$SalesInThousands)

vallmR2 <- validationlm %>% 
  mutate(res2 = (SalesInThousands - predicted)^2 ,
         tot2 = (SalesInThousands - mean_SalesInThousands_val)^2)

r2 <- 1- sum(vallmR2$res2)/sum(vallmR2$tot2)

Scoring the validation data set

##     Min.  1st Qu.   Median     Mean  3rd Qu.     Max. 
## 0.001237 0.031558 0.065261 0.094147 0.126537 0.575793

##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
## 

```