Data prep for modeling

Data Summary: The variables:store, and holiday flag are continuous but should be categorical

##      Store        Date            Weekly_Sales      Holiday_Flag    
##  Min.   : 1   Length:6435        Min.   : 209986   Min.   :0.00000  
##  1st Qu.:12   Class :character   1st Qu.: 553350   1st Qu.:0.00000  
##  Median :23   Mode  :character   Median : 960746   Median :0.00000  
##  Mean   :23                      Mean   :1046965   Mean   :0.06993  
##  3rd Qu.:34                      3rd Qu.:1420159   3rd Qu.:0.00000  
##  Max.   :45                      Max.   :3818686   Max.   :1.00000  
##   Temperature       Fuel_Price         CPI         Unemployment   
##  Min.   : -2.06   Min.   :2.472   Min.   :126.1   Min.   : 3.879  
##  1st Qu.: 47.46   1st Qu.:2.933   1st Qu.:131.7   1st Qu.: 6.891  
##  Median : 62.67   Median :3.445   Median :182.6   Median : 7.874  
##  Mean   : 60.66   Mean   :3.359   Mean   :171.6   Mean   : 7.999  
##  3rd Qu.: 74.94   3rd Qu.:3.735   3rd Qu.:212.7   3rd Qu.: 8.622  
##  Max.   :100.14   Max.   :4.468   Max.   :227.2   Max.   :14.313

Data Summary now with categorical variables as factors, and a random variable for splitting the data

##      Store          Date            Weekly_Sales     Holiday_Flag
##  1      : 143   Length:6435        Min.   : 209986   0:5985      
##  2      : 143   Class :character   1st Qu.: 553350   1: 450      
##  3      : 143   Mode  :character   Median : 960746               
##  4      : 143                      Mean   :1046965               
##  5      : 143                      3rd Qu.:1420159               
##  6      : 143                      Max.   :3818686               
##  (Other):5577                                                    
##   Temperature       Fuel_Price         CPI         Unemployment   
##  Min.   : -2.06   Min.   :2.472   Min.   :126.1   Min.   : 3.879  
##  1st Qu.: 47.46   1st Qu.:2.933   1st Qu.:131.7   1st Qu.: 6.891  
##  Median : 62.67   Median :3.445   Median :182.6   Median : 7.874  
##  Mean   : 60.66   Mean   :3.359   Mean   :171.6   Mean   : 7.999  
##  3rd Qu.: 74.94   3rd Qu.:3.735   3rd Qu.:212.7   3rd Qu.: 8.622  
##  Max.   :100.14   Max.   :4.468   Max.   :227.2   Max.   :14.313  
##                                                                   
##      random         
##  Min.   :0.0000653  
##  1st Qu.:0.2527042  
##  Median :0.4945870  
##  Mean   :0.4980825  
##  3rd Qu.:0.7453083  
##  Max.   :0.9999414  
## 
## tibble [6,435 × 9] (S3: tbl_df/tbl/data.frame)
##  $ Store       : Factor w/ 45 levels "1","2","3","4",..: 1 1 1 1 1 1 1 1 1 1 ...
##  $ Date        : chr [1:6435] "05-02-2010" "12-02-2010" "19-02-2010" "26-02-2010" ...
##  $ Weekly_Sales: num [1:6435] 1643691 1641957 1611968 1409728 1554807 ...
##  $ Holiday_Flag: Factor w/ 2 levels "0","1": 1 2 1 1 1 1 1 1 1 1 ...
##  $ Temperature : num [1:6435] 42.3 38.5 39.9 46.6 46.5 ...
##  $ Fuel_Price  : num [1:6435] 2.57 2.55 2.51 2.56 2.62 ...
##  $ CPI         : num [1:6435] 211 211 211 211 211 ...
##  $ Unemployment: num [1:6435] 8.11 8.11 8.11 8.11 8.11 ...
##  $ random      : num [1:6435] 0.288 0.788 0.409 0.883 0.94 ...

Data split 70/30 into training and validation datasets.

Linear model to predict sales

  1. A linear model was created using all possible predictors, except for Date, predicting sales. This model allowed for the understanding of the individual effects of each predictor.
  2. Then a model with all possible interactions was created, again, excluding Date
  3. A backward selection was employed using alpha = 0.01 in order to obtain a more parsimonious model.
  4. The resulting model with interactions, as well as the initial model without, can be found in the Appendix
## Backward Elimination Method 
## ---------------------------
## 
## Candidate Terms: 
## 
## 1. Store 
## 2. Holiday_Flag 
## 3. Temperature 
## 4. Fuel_Price 
## 5. CPI 
## 6. Unemployment 
## 7. Store:Holiday_Flag 
## 8. Store:Temperature 
## 9. Store:Fuel_Price 
## 10. Store:CPI 
## 11. Store:Unemployment 
## 12. Holiday_Flag:Temperature 
## 13. Holiday_Flag:Fuel_Price 
## 14. Holiday_Flag:CPI 
## 15. Holiday_Flag:Unemployment 
## 16. Temperature:Fuel_Price 
## 17. Temperature:CPI 
## 18. Temperature:Unemployment 
## 19. Fuel_Price:CPI 
## 20. Fuel_Price:Unemployment 
## 21. CPI:Unemployment 
## 
## 
## Step   => 0 
## Model  => Weekly_Sales ~ Store + Holiday_Flag + Temperature + Fuel_Price + CPI + Unemployment + Store:Holiday_Flag + Store:Temperature + Store:Fuel_Price + Store:CPI + Store:Unemployment + Holiday_Flag:Temperature + Holiday_Flag:Fuel_Price + Holiday_Flag:CPI + Holiday_Flag:Unemployment + Temperature:Fuel_Price + Temperature:CPI + Temperature:Unemployment + Fuel_Price:CPI + Fuel_Price:Unemployment + CPI:Unemployment 
## R2     => 0.93 
## 
## Initiating stepwise selection... 
## 
## Step     => 1 
## Removed  => Unemployment 
## Model    => Weekly_Sales ~ Store + Holiday_Flag + Temperature + Fuel_Price + CPI + Store:Holiday_Flag + Store:Temperature + Store:Fuel_Price + Store:CPI + Store:Unemployment + Holiday_Flag:Temperature + Holiday_Flag:Fuel_Price + Holiday_Flag:CPI + Holiday_Flag:Unemployment + Temperature:Fuel_Price + Temperature:CPI + Temperature:Unemployment + Fuel_Price:CPI + Fuel_Price:Unemployment + CPI:Unemployment 
## R2       => 0.93027 
## 
## Step     => 2 
## Removed  => Holiday_Flag:CPI 
## Model    => Weekly_Sales ~ Store + Holiday_Flag + Temperature + Fuel_Price + CPI + Store:Holiday_Flag + Store:Temperature + Store:Fuel_Price + Store:CPI + Store:Unemployment + Holiday_Flag:Temperature + Holiday_Flag:Fuel_Price + Holiday_Flag:Unemployment + Temperature:Fuel_Price + Temperature:CPI + Temperature:Unemployment + Fuel_Price:CPI + Fuel_Price:Unemployment + CPI:Unemployment 
## R2       => 0.93027 
## 
## Step     => 3 
## Removed  => Fuel_Price:Unemployment 
## Model    => Weekly_Sales ~ Store + Holiday_Flag + Temperature + Fuel_Price + CPI + Store:Holiday_Flag + Store:Temperature + Store:Fuel_Price + Store:CPI + Store:Unemployment + Holiday_Flag:Temperature + Holiday_Flag:Fuel_Price + Holiday_Flag:Unemployment + Temperature:Fuel_Price + Temperature:CPI + Temperature:Unemployment + Fuel_Price:CPI + CPI:Unemployment 
## R2       => 0.93027 
## 
## Step     => 4 
## Removed  => CPI:Unemployment 
## Model    => Weekly_Sales ~ Store + Holiday_Flag + Temperature + Fuel_Price + CPI + Store:Holiday_Flag + Store:Temperature + Store:Fuel_Price + Store:CPI + Store:Unemployment + Holiday_Flag:Temperature + Holiday_Flag:Fuel_Price + Holiday_Flag:Unemployment + Temperature:Fuel_Price + Temperature:CPI + Temperature:Unemployment + Fuel_Price:CPI 
## R2       => 0.93026 
## 
## Step     => 5 
## Removed  => Store:Fuel_Price 
## Model    => Weekly_Sales ~ Store + Holiday_Flag + Temperature + Fuel_Price + CPI + Store:Holiday_Flag + Store:Temperature + Store:CPI + Store:Unemployment + Holiday_Flag:Temperature + Holiday_Flag:Fuel_Price + Holiday_Flag:Unemployment + Temperature:Fuel_Price + Temperature:CPI + Temperature:Unemployment + Fuel_Price:CPI 
## R2       => 0.92952 
## 
## 
## No more variables to be removed.
## 
## Variables Removed: 
## 
## => Unemployment 
## => Holiday_Flag:CPI 
## => Fuel_Price:Unemployment 
## => CPI:Unemployment 
## => Store:Fuel_Price

Interpretations of three predictors

Fuel Price: When fuel prices go up, sales go down
Holiday_Flag1: Sales increase during holidays
CPI: As CPI goes up, so do sales
The model, using the training data, has an r^2 .9311
The model, using the validation data, has an r^2 .925

Appendix

Model without interactions

## 
## Call:
## lm(formula = Weekly_Sales ~ . - Date, data = trainlm)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -513804  -69546  -11882   39468 1823766 
## 
## Coefficients:
##                 Estimate Std. Error t value Pr(>|t|)    
## (Intercept)    1357543.2   278781.6   4.870 1.16e-06 ***
## Store2          351630.2    22573.7  15.577  < 2e-16 ***
## Store3        -1180716.9    23170.7 -50.957  < 2e-16 ***
## Store4          716535.6   116599.9   6.145 8.68e-10 ***
## Store5        -1282576.3    24140.1 -53.131  < 2e-16 ***
## Store6          -42348.2    23255.9  -1.821 0.068679 .  
## Store7         -946003.2    35215.5 -26.863  < 2e-16 ***
## Store8         -699172.6    23983.0 -29.153  < 2e-16 ***
## Store9        -1068955.1    23877.8 -44.768  < 2e-16 ***
## Store10         628887.4   112929.0   5.569 2.71e-08 ***
## Store11        -217449.3    23756.1  -9.153  < 2e-16 ***
## Store12        -160159.8   105614.7  -1.516 0.129475    
## Store13         665390.8   114607.5   5.806 6.85e-09 ***
## Store14         541155.6    43009.0  12.582  < 2e-16 ***
## Store15        -711503.8   105846.8  -6.722 2.02e-11 ***
## Store16       -1033264.4    39281.3 -26.304  < 2e-16 ***
## Store17        -482891.3   115651.4  -4.175 3.03e-05 ***
## Store18        -236188.4   103207.7  -2.288 0.022156 *  
## Store19          88916.7   105944.5   0.839 0.401359    
## Store20         568352.9    25871.2  21.969  < 2e-16 ***
## Store21        -815160.0    22958.8 -35.505  < 2e-16 ***
## Store22        -323211.6   100196.3  -3.226 0.001265 ** 
## Store23         -29770.2   113150.0  -0.263 0.792482    
## Store24          27496.8   104872.5   0.262 0.793185    
## Store25        -847649.9    25399.5 -33.373  < 2e-16 ***
## Store26        -359445.5   105525.4  -3.406 0.000664 ***
## Store27         439229.1   101050.9   4.347 1.41e-05 ***
## Store28         139953.5   105779.4   1.323 0.185880    
## Store29        -750276.3   101676.3  -7.379 1.89e-13 ***
## Store30       -1122743.3    22425.9 -50.065  < 2e-16 ***
## Store31        -158464.1    22737.4  -6.969 3.65e-12 ***
## Store32        -332244.3    35092.7  -9.468  < 2e-16 ***
## Store33       -1023329.2   112745.7  -9.076  < 2e-16 ***
## Store34        -312719.9   107897.4  -2.898 0.003770 ** 
## Store35        -415109.3    98516.6  -4.214 2.56e-05 ***
## Store36       -1180433.3    23588.0 -50.044  < 2e-16 ***
## Store37       -1035121.3    22767.4 -45.465  < 2e-16 ***
## Store38        -796167.5   105624.2  -7.538 5.75e-14 ***
## Store39         -86778.8    23088.3  -3.759 0.000173 ***
## Store40        -455869.6   113041.5  -4.033 5.60e-05 ***
## Store41        -279251.2    37950.0  -7.358 2.20e-13 ***
## Store42        -730734.7   113110.0  -6.460 1.16e-10 ***
## Store43        -857065.6    25926.2 -33.058  < 2e-16 ***
## Store44       -1056135.9   115347.2  -9.156  < 2e-16 ***
## Store45        -676430.4    43141.6 -15.679  < 2e-16 ***
## Holiday_Flag1    75352.5     9602.9   7.847 5.30e-15 ***
## Temperature       -904.9      159.4  -5.677 1.46e-08 ***
## Fuel_Price      -42007.4     8681.7  -4.839 1.35e-06 ***
## CPI               2692.5     1262.7   2.132 0.033030 *  
## Unemployment    -23933.5     5245.3  -4.563 5.18e-06 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 162300 on 4475 degrees of freedom
## Multiple R-squared:  0.9183, Adjusted R-squared:  0.9174 
## F-statistic:  1027 on 49 and 4475 DF,  p-value: < 2.2e-16

Model with interactions

## 
## Call:
## lm(formula = paste(response, "~", paste(c(include, cterms), collapse = " + ")), 
##     data = l)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -587129  -57713   -9239   31164 1669777 
## 
## Coefficients:
##                              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)                -5.552e+06  2.067e+06  -2.686 0.007251 ** 
## Store2                      1.390e+06  3.731e+06   0.372 0.709572    
## Store3                     -7.319e+05  2.495e+06  -0.293 0.769288    
## Store4                      2.277e+06  4.832e+06   0.471 0.637543    
## Store5                     -3.365e+05  3.015e+06  -0.112 0.911122    
## Store6                     -3.187e+05  3.202e+06  -0.100 0.920710    
## Store7                     -7.687e+06  4.412e+06  -1.742 0.081509 .  
## Store8                     -7.409e+05  2.607e+06  -0.284 0.776265    
## Store9                     -2.417e+06  2.943e+06  -0.821 0.411532    
## Store10                     1.530e+07  4.841e+06   3.161 0.001581 ** 
## Store11                     3.802e+05  2.493e+06   0.153 0.878791    
## Store12                     6.552e+05  3.325e+06   0.197 0.843815    
## Store13                     1.635e+07  5.779e+06   2.830 0.004676 ** 
## Store14                     1.287e+07  2.550e+06   5.048 4.65e-07 ***
## Store15                     4.437e+06  2.167e+06   2.047 0.040698 *  
## Store16                     1.478e+06  3.789e+06   0.390 0.696566    
## Store17                     8.385e+05  2.607e+06   0.322 0.747771    
## Store18                     6.805e+06  4.054e+06   1.679 0.093295 .  
## Store19                     5.823e+06  2.181e+06   2.670 0.007609 ** 
## Store20                     4.292e+06  2.388e+06   1.797 0.072386 .  
## Store21                    -5.944e+06  3.926e+06  -1.514 0.130123    
## Store22                     5.058e+06  3.706e+06   1.365 0.172374    
## Store23                     7.387e+06  5.375e+06   1.374 0.169378    
## Store24                     4.762e+06  2.117e+06   2.249 0.024554 *  
## Store25                     3.642e+06  2.359e+06   1.544 0.122680    
## Store26                     5.105e+06  5.208e+06   0.980 0.327070    
## Store27                     7.757e+06  2.077e+06   3.734 0.000191 ***
## Store28                     5.090e+06  3.439e+06   1.480 0.138904    
## Store29                     1.996e+06  3.480e+06   0.573 0.566395    
## Store30                     1.817e+06  3.787e+06   0.480 0.631345    
## Store31                    -4.447e+06  3.928e+06  -1.132 0.257554    
## Store32                    -4.202e+06  4.346e+06  -0.967 0.333632    
## Store33                     2.755e+06  5.164e+06   0.534 0.593699    
## Store34                     3.041e+06  2.245e+06   1.354 0.175665    
## Store35                     4.901e+06  2.239e+06   2.188 0.028694 *  
## Store36                     3.601e+06  3.489e+06   1.032 0.302085    
## Store37                     9.487e+04  3.350e+06   0.028 0.977412    
## Store38                     2.959e+05  3.365e+06   0.088 0.929921    
## Store39                    -6.233e+06  3.382e+06  -1.843 0.065413 .  
## Store40                     5.915e+06  5.705e+06   1.037 0.299907    
## Store41                    -6.364e+05  5.167e+06  -0.123 0.901977    
## Store42                     3.138e+06  5.207e+06   0.603 0.546745    
## Store43                     2.658e+06  2.004e+06   1.326 0.184755    
## Store44                     3.456e+06  5.990e+06   0.577 0.564001    
## Store45                     1.855e+06  2.704e+06   0.686 0.492794    
## Holiday_Flag1               4.297e+05  2.521e+05   1.704 0.088454 .  
## Temperature                 4.481e+04  1.894e+04   2.365 0.018050 *  
## Fuel_Price                 -8.552e+04  6.073e+04  -1.408 0.159165    
## CPI                         3.160e+04  8.103e+03   3.900 9.78e-05 ***
## Store2:Holiday_Flag1       -5.246e+04  9.013e+04  -0.582 0.560556    
## Store3:Holiday_Flag1       -9.513e+04  9.088e+04  -1.047 0.295295    
## Store4:Holiday_Flag1       -8.738e+04  1.093e+05  -0.799 0.424157    
## Store5:Holiday_Flag1       -1.324e+05  9.447e+04  -1.402 0.161074    
## Store6:Holiday_Flag1       -5.329e+04  9.321e+04  -0.572 0.567508    
## Store7:Holiday_Flag1        9.233e+03  9.443e+04   0.098 0.922121    
## Store8:Holiday_Flag1       -1.035e+05  1.013e+05  -1.021 0.307234    
## Store9:Holiday_Flag1       -1.581e+05  9.421e+04  -1.678 0.093417 .  
## Store10:Holiday_Flag1       1.723e+04  8.807e+04   0.196 0.844895    
## Store11:Holiday_Flag1      -1.497e+05  9.904e+04  -1.511 0.130801    
## Store12:Holiday_Flag1       2.564e+05  1.610e+05   1.593 0.111217    
## Store13:Holiday_Flag1       8.884e+03  9.284e+04   0.096 0.923769    
## Store14:Holiday_Flag1       4.812e+04  8.870e+04   0.542 0.587509    
## Store15:Holiday_Flag1      -8.486e+04  9.339e+04  -0.909 0.363561    
## Store16:Holiday_Flag1      -1.058e+05  1.021e+05  -1.036 0.300240    
## Store17:Holiday_Flag1      -7.390e+03  9.233e+04  -0.080 0.936209    
## Store18:Holiday_Flag1       1.523e+05  1.084e+05   1.404 0.160372    
## Store19:Holiday_Flag1       1.172e+05  8.891e+04   1.318 0.187440    
## Store20:Holiday_Flag1      -4.434e+04  8.670e+04  -0.511 0.609055    
## Store21:Holiday_Flag1      -8.342e+04  8.939e+04  -0.933 0.350770    
## Store22:Holiday_Flag1      -3.481e+04  9.641e+04  -0.361 0.718101    
## Store23:Holiday_Flag1      -1.684e+04  1.077e+05  -0.156 0.875741    
## Store24:Holiday_Flag1       1.291e+05  9.380e+04   1.376 0.168860    
## Store25:Holiday_Flag1      -3.212e+04  9.119e+04  -0.352 0.724660    
## Store26:Holiday_Flag1       5.135e+04  9.684e+04   0.530 0.595933    
## Store27:Holiday_Flag1       1.666e+05  8.991e+04   1.852 0.064032 .  
## Store28:Holiday_Flag1       3.018e+05  1.614e+05   1.870 0.061600 .  
## Store29:Holiday_Flag1       1.141e+05  1.107e+05   1.031 0.302754    
## Store30:Holiday_Flag1      -1.109e+05  9.046e+04  -1.226 0.220313    
## Store31:Holiday_Flag1      -7.891e+02  8.912e+04  -0.009 0.992935    
## Store32:Holiday_Flag1      -5.212e+04  9.426e+04  -0.553 0.580318    
## Store33:Holiday_Flag1      -8.074e+04  9.401e+04  -0.859 0.390489    
## Store34:Holiday_Flag1       7.672e+04  1.009e+05   0.761 0.446987    
## Store35:Holiday_Flag1       1.480e+05  9.095e+04   1.627 0.103734    
## Store36:Holiday_Flag1      -1.072e+05  9.108e+04  -1.177 0.239091    
## Store37:Holiday_Flag1      -1.292e+05  8.872e+04  -1.456 0.145477    
## Store38:Holiday_Flag1       1.216e+05  1.582e+05   0.769 0.442167    
## Store39:Holiday_Flag1       2.622e+04  8.911e+04   0.294 0.768597    
## Store40:Holiday_Flag1      -1.154e+05  1.078e+05  -1.071 0.284396    
## Store41:Holiday_Flag1      -4.886e+04  9.344e+04  -0.523 0.601045    
## Store42:Holiday_Flag1      -2.231e+04  1.161e+05  -0.192 0.847651    
## Store43:Holiday_Flag1      -1.721e+04  1.021e+05  -0.169 0.866141    
## Store44:Holiday_Flag1      -1.229e+05  9.314e+04  -1.320 0.186883    
## Store45:Holiday_Flag1      -3.279e+04  9.818e+04  -0.334 0.738392    
## Store2:Temperature         -1.095e+03  1.530e+03  -0.716 0.474184    
## Store3:Temperature          1.198e+03  1.684e+03   0.711 0.476871    
## Store4:Temperature         -2.316e+04  7.919e+03  -2.925 0.003465 ** 
## Store5:Temperature          1.064e+03  1.711e+03   0.622 0.534237    
## Store6:Temperature          8.358e+02  1.585e+03   0.527 0.597949    
## Store7:Temperature         -1.267e+03  2.290e+03  -0.553 0.580193    
## Store8:Temperature         -1.569e+03  1.611e+03  -0.974 0.330308    
## Store9:Temperature          8.142e+02  1.599e+03   0.509 0.610613    
## Store10:Temperature        -2.741e+04  7.675e+03  -3.571 0.000359 ***
## Store11:Temperature        -2.774e+03  1.817e+03  -1.527 0.126884    
## Store12:Temperature        -1.635e+04  7.191e+03  -2.274 0.023010 *  
## Store13:Temperature        -2.057e+04  7.731e+03  -2.661 0.007818 ** 
## Store14:Temperature        -5.019e+03  2.911e+03  -1.724 0.084760 .  
## Store15:Temperature        -1.628e+04  7.176e+03  -2.268 0.023350 *  
## Store16:Temperature        -1.694e+03  2.543e+03  -0.666 0.505322    
## Store17:Temperature        -1.659e+04  7.766e+03  -2.137 0.032684 *  
## Store18:Temperature        -1.536e+04  7.046e+03  -2.181 0.029274 *  
## Store19:Temperature        -1.429e+04  7.175e+03  -1.992 0.046457 *  
## Store20:Temperature        -6.260e+03  1.679e+03  -3.729 0.000194 ***
## Store21:Temperature         1.114e+03  1.542e+03   0.722 0.470140    
## Store22:Temperature        -1.465e+04  6.814e+03  -2.150 0.031626 *  
## Store23:Temperature        -1.679e+04  7.620e+03  -2.204 0.027577 *  
## Store24:Temperature        -1.388e+04  7.101e+03  -1.955 0.050626 .  
## Store25:Temperature        -3.020e+02  1.626e+03  -0.186 0.852691    
## Store26:Temperature        -1.348e+04  7.169e+03  -1.880 0.060182 .  
## Store27:Temperature        -1.114e+04  6.867e+03  -1.623 0.104742    
## Store28:Temperature        -1.735e+04  7.202e+03  -2.409 0.016020 *  
## Store29:Temperature        -1.550e+04  6.916e+03  -2.241 0.025086 *  
## Store30:Temperature         1.564e+03  1.493e+03   1.047 0.294966    
## Store31:Temperature        -6.441e+01  1.505e+03  -0.043 0.965864    
## Store32:Temperature        -1.443e+03  2.276e+03  -0.634 0.526144    
## Store33:Temperature        -1.642e+04  7.663e+03  -2.143 0.032200 *  
## Store34:Temperature        -1.640e+04  7.304e+03  -2.246 0.024784 *  
## Store35:Temperature        -1.216e+04  6.678e+03  -1.821 0.068641 .  
## Store36:Temperature         2.243e+03  1.769e+03   1.268 0.204797    
## Store37:Temperature         1.299e+03  1.774e+03   0.732 0.464136    
## Store38:Temperature        -1.341e+04  7.191e+03  -1.865 0.062245 .  
## Store39:Temperature         1.253e+03  1.772e+03   0.707 0.479501    
## Store40:Temperature        -1.709e+04  7.616e+03  -2.244 0.024885 *  
## Store41:Temperature        -2.007e+03  2.471e+03  -0.812 0.416633    
## Store42:Temperature        -1.765e+04  7.691e+03  -2.295 0.021797 *  
## Store43:Temperature         2.706e+03  1.768e+03   1.531 0.125943    
## Store44:Temperature        -1.703e+04  7.772e+03  -2.192 0.028469 *  
## Store45:Temperature        -5.881e+03  2.911e+03  -2.021 0.043393 *  
## Store2:CPI                 -3.984e+03  1.373e+04  -0.290 0.771615    
## Store3:CPI                 -1.884e+03  8.854e+03  -0.213 0.831505    
## Store4:CPI                  1.636e+04  3.310e+04   0.494 0.621138    
## Store5:CPI                 -3.637e+03  1.054e+04  -0.345 0.730155    
## Store6:CPI                  5.566e+02  1.174e+04   0.047 0.962178    
## Store7:CPI                  2.905e+04  1.684e+04   1.725 0.084599 .  
## Store8:CPI                 -1.772e+02  9.072e+03  -0.020 0.984414    
## Store9:CPI                  4.960e+03  1.052e+04   0.471 0.637368    
## Store10:CPI                -7.895e+04  3.113e+04  -2.536 0.011254 *  
## Store11:CPI                -1.555e+03  8.773e+03  -0.177 0.859318    
## Store12:CPI                 1.182e+04  1.995e+04   0.593 0.553504    
## Store13:CPI                -8.652e+04  3.889e+04  -2.224 0.026177 *  
## Store14:CPI                -5.105e+04  7.972e+03  -6.404 1.68e-10 ***
## Store15:CPI                -1.704e+04  9.455e+03  -1.803 0.071526 .  
## Store16:CPI                -7.981e+03  1.469e+04  -0.543 0.586898    
## Store17:CPI                 1.216e+04  1.336e+04   0.911 0.362525    
## Store18:CPI                -3.029e+04  2.131e+04  -1.422 0.155210    
## Store19:CPI                -2.164e+04  9.544e+03  -2.267 0.023416 *  
## Store20:CPI                -9.873e+03  8.240e+03  -1.198 0.230905    
## Store21:CPI                 1.784e+04  1.449e+04   1.231 0.218434    
## Store22:CPI                -1.726e+04  1.868e+04  -0.924 0.355321    
## Store23:CPI                -2.980e+04  3.306e+04  -0.901 0.367522    
## Store24:CPI                -1.833e+04  1.475e+04  -1.243 0.214011    
## Store25:CPI                -1.623e+04  8.209e+03  -1.977 0.048075 *  
## Store26:CPI                -1.723e+04  2.815e+04  -0.612 0.540529    
## Store27:CPI                -2.469e+04  9.454e+03  -2.612 0.009045 ** 
## Store28:CPI                -1.706e+04  2.084e+04  -0.819 0.412923    
## Store29:CPI                -2.620e+03  1.835e+04  -0.143 0.886478    
## Store30:CPI                -1.173e+04  1.401e+04  -0.837 0.402527    
## Store31:CPI                 1.679e+04  1.447e+04   1.160 0.245990    
## Store32:CPI                 1.626e+04  1.656e+04   0.982 0.326170    
## Store33:CPI                -8.609e+03  3.387e+04  -0.254 0.799368    
## Store34:CPI                -5.108e+03  1.133e+04  -0.451 0.652107    
## Store35:CPI                -4.449e+04  9.285e+03  -4.792 1.71e-06 ***
## Store36:CPI                -2.107e+04  1.321e+04  -1.596 0.110647    
## Store37:CPI                -4.330e+03  1.250e+04  -0.346 0.729101    
## Store38:CPI                 1.017e+04  2.022e+04   0.503 0.615018    
## Store39:CPI                 2.711e+04  1.264e+04   2.145 0.031989 *  
## Store40:CPI                -2.284e+04  3.525e+04  -0.648 0.517056    
## Store41:CPI                 8.858e+03  2.027e+04   0.437 0.662101    
## Store42:CPI                -6.583e+03  3.387e+04  -0.194 0.845895    
## Store43:CPI                -1.430e+04  7.218e+03  -1.982 0.047577 *  
## Store44:CPI                -1.094e+04  4.070e+04  -0.269 0.788163    
## Store45:CPI                -8.683e+03  8.400e+03  -1.034 0.301355    
## Store1:Unemployment         1.237e+05  7.030e+04   1.759 0.078594 .  
## Store2:Unemployment         1.110e+05  9.207e+04   1.205 0.228208    
## Store3:Unemployment         1.078e+05  6.841e+04   1.576 0.115002    
## Store4:Unemployment        -9.468e+03  4.513e+04  -0.210 0.833838    
## Store5:Unemployment         1.073e+05  1.028e+05   1.043 0.297040    
## Store6:Unemployment         1.507e+05  8.846e+04   1.703 0.088579 .  
## Store7:Unemployment         2.929e+05  1.210e+05   2.421 0.015538 *  
## Store8:Unemployment         1.707e+05  9.007e+04   1.895 0.058124 .  
## Store9:Unemployment         1.750e+05  9.134e+04   1.916 0.055476 .  
## Store10:Unemployment       -6.044e+04  7.134e+04  -0.847 0.396948    
## Store11:Unemployment        1.178e+05  7.115e+04   1.656 0.097756 .  
## Store12:Unemployment        7.588e+04  4.165e+04   1.822 0.068547 .  
## Store13:Unemployment       -1.594e+05  7.912e+04  -2.015 0.044006 *  
## Store14:Unemployment       -1.292e+05  1.330e+05  -0.972 0.331263    
## Store15:Unemployment        3.623e+04  8.476e+04   0.428 0.669034    
## Store16:Unemployment        6.610e+04  1.268e+05   0.521 0.602073    
## Store17:Unemployment        5.289e+04  7.337e+04   0.721 0.470984    
## Store18:Unemployment        1.516e+04  1.110e+05   0.137 0.891376    
## Store19:Unemployment        2.623e+04  8.743e+04   0.300 0.764220    
## Store20:Unemployment       -3.593e+04  8.298e+04  -0.433 0.665076    
## Store21:Unemployment        2.831e+05  9.785e+04   2.893 0.003837 ** 
## Store22:Unemployment       -2.967e+02  1.111e+05  -0.003 0.997870    
## Store23:Unemployment       -5.880e+04  1.424e+05  -0.413 0.679605    
## Store24:Unemployment        8.775e+04  1.099e+05   0.799 0.424523    
## Store25:Unemployment       -4.563e+03  7.617e+04  -0.060 0.952233    
## Store26:Unemployment       -1.673e+04  1.584e+05  -0.106 0.915896    
## Store27:Unemployment       -1.406e+05  1.012e+05  -1.389 0.164769    
## Store28:Unemployment        4.933e+04  4.199e+04   1.175 0.240137    
## Store29:Unemployment        7.309e+04  7.693e+04   0.950 0.342162    
## Store30:Unemployment        5.703e+04  9.269e+04   0.615 0.538403    
## Store31:Unemployment        2.122e+05  9.782e+04   2.169 0.030146 *  
## Store32:Unemployment        2.458e+05  1.213e+05   2.027 0.042775 *  
## Store33:Unemployment        6.520e+04  6.763e+04   0.964 0.335101    
## Store34:Unemployment        5.675e+04  4.105e+04   1.383 0.166880    
## Store35:Unemployment        4.210e+05  8.992e+04   4.682 2.93e-06 ***
## Store36:Unemployment        7.127e+04  7.510e+04   0.949 0.342652    
## Store37:Unemployment        8.717e+04  7.387e+04   1.180 0.238059    
## Store38:Unemployment        5.625e+04  4.155e+04   1.354 0.175924    
## Store39:Unemployment        1.525e+05  7.540e+04   2.022 0.043201 *  
## Store40:Unemployment       -3.171e+04  1.536e+05  -0.206 0.836470    
## Store41:Unemployment        6.928e+03  1.637e+05   0.042 0.966238    
## Store42:Unemployment        3.416e+04  7.547e+04   0.453 0.650808    
## Store43:Unemployment        3.884e+04  4.529e+04   0.857 0.391234    
## Store44:Unemployment        2.175e+04  7.938e+04   0.274 0.784105    
## Store45:Unemployment        9.742e+04  1.397e+05   0.698 0.485472    
## Holiday_Flag1:Temperature   1.481e+03  5.939e+02   2.494 0.012675 *  
## Holiday_Flag1:Fuel_Price   -3.641e+04  3.376e+04  -1.079 0.280819    
## Holiday_Flag1:Unemployment -3.897e+04  2.189e+04  -1.780 0.075111 .  
## Temperature:Fuel_Price      1.509e+03  6.036e+02   2.500 0.012467 *  
## Temperature:CPI            -2.142e+02  8.638e+01  -2.480 0.013187 *  
## Temperature:Unemployment   -7.086e+02  3.563e+02  -1.989 0.046797 *  
## Fuel_Price:CPI             -3.532e+02  2.973e+02  -1.188 0.234868    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 153900 on 4292 degrees of freedom
## Multiple R-squared:  0.9295, Adjusted R-squared:  0.9257 
## F-statistic:   244 on 232 and 4292 DF,  p-value: < 2.2e-16