(4a)Issues being faced by management and list of most important questions.

  1. How store-level employee retention can be increased?

  2. What is the effect of Manager and Crew Tenure on profit in stores?

  3. What are the strategies to increase Tenure?

  4. Are there any other factors that have an financial impact on sales and profit besides tenure?

(4b)How might a dataset associated with Exhibit 2 in case study help in answering your list of questions from Task (4a)

The dataset asociated in Exhibit 2 may help us understand the relationship between the dependent variable(Profit) and the other independent variables. By performing analysis and tests, we can determine whether to what extent the profit or sales in Store24 stores are impacted by the factors(variables) in the dataset. Therefore we can determine what variables or factors are to be focused on in order to improve sales and profit and what variables or factors are to be neglected.

(4c)Reading & Summary

setwd("C:/Users/Shreyas Jadhav/Downloads")  
store.df <- read.csv(paste("Store24.csv",sep="."))
#View(store.df)
summary(store.df)
##      store          Sales             Profit          MTenure      
##  Min.   : 1.0   Min.   : 699306   Min.   :122180   Min.   :  0.00  
##  1st Qu.:19.5   1st Qu.: 984579   1st Qu.:211004   1st Qu.:  6.67  
##  Median :38.0   Median :1127332   Median :265014   Median : 24.12  
##  Mean   :38.0   Mean   :1205413   Mean   :276314   Mean   : 45.30  
##  3rd Qu.:56.5   3rd Qu.:1362388   3rd Qu.:331314   3rd Qu.: 50.92  
##  Max.   :75.0   Max.   :2113089   Max.   :518998   Max.   :277.99  
##     CTenure              Pop             Comp          Visibility  
##  Min.   :  0.8871   Min.   : 1046   Min.   : 1.651   Min.   :2.00  
##  1st Qu.:  4.3943   1st Qu.: 5616   1st Qu.: 3.151   1st Qu.:3.00  
##  Median :  7.2115   Median : 8896   Median : 3.629   Median :3.00  
##  Mean   : 13.9315   Mean   : 9826   Mean   : 3.788   Mean   :3.08  
##  3rd Qu.: 17.2156   3rd Qu.:14104   3rd Qu.: 4.230   3rd Qu.:4.00  
##  Max.   :114.1519   Max.   :26519   Max.   :11.128   Max.   :5.00  
##     PedCount         Res          Hours24       CrewSkill    
##  Min.   :1.00   Min.   :0.00   Min.   :0.00   Min.   :2.060  
##  1st Qu.:2.00   1st Qu.:1.00   1st Qu.:1.00   1st Qu.:3.225  
##  Median :3.00   Median :1.00   Median :1.00   Median :3.500  
##  Mean   :2.96   Mean   :0.96   Mean   :0.84   Mean   :3.457  
##  3rd Qu.:4.00   3rd Qu.:1.00   3rd Qu.:1.00   3rd Qu.:3.655  
##  Max.   :5.00   Max.   :1.00   Max.   :1.00   Max.   :4.640  
##     MgrSkill        ServQual     
##  Min.   :2.957   Min.   : 57.90  
##  1st Qu.:3.344   1st Qu.: 78.95  
##  Median :3.589   Median : 89.47  
##  Mean   :3.638   Mean   : 87.15  
##  3rd Qu.:3.925   3rd Qu.: 99.90  
##  Max.   :4.622   Max.   :100.00
attach(store.df)

Therefore, the summary statistics generated from R are consistent with Exhibit 3 from the Case.

Analysis

(4d)The mean and standard deviation of:

(1)1.Profit

mean(store.df$Profit)
## [1] 276313.6
sd(store.df$Profit)
## [1] 89404.08

Therefore, the mean and standard deviation of profit is $276313.6 and $89404.08respectively.

(2)2.MTenure

mean(store.df$MTenure)
## [1] 45.29644
sd(store.df$MTenure)
## [1] 57.67155

Therefore, the mean and standard deviation of MTenure is 45.29644 and 57.67155respectively.

(3)3.CTenure

mean(store.df$CTenure)
## [1] 13.9315
sd(store.df$CTenure)
## [1] 17.69752

Therefore, the mean and standard deviation of CTenure is 13.9315 and 17.69752respectively.

(4e)Sort a dataframe based on a data column.(Example)

attach(mtcars)
View(mtcars)
newdata <- mtcars[order(mpg),] # sort by mpg (ascending)
View(newdata)
newdata[1:5,] # see the first 5 rows
##                      mpg cyl disp  hp drat    wt  qsec vs am gear carb
## Cadillac Fleetwood  10.4   8  472 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8  460 215 3.00 5.424 17.82  0  0    3    4
## Camaro Z28          13.3   8  350 245 3.73 3.840 15.41  0  0    3    4
## Duster 360          14.3   8  360 245 3.21 3.570 15.84  0  0    3    4
## Chrysler Imperial   14.7   8  440 230 3.23 5.345 17.42  0  0    3    4
newdata <- mtcars[order(-mpg),] # sort by mpg (descending)
View(newdata)
detach(mtcars)

(4f)Use R to:

(4)1. Print the {StoreID, Sales, Profit, MTenure, CTenure} of the top 10 most profitable stores.

newdata1<-store.df[order(-store.df$Profit),]
newdata1[1:10,1:5]
##    store   Sales Profit   MTenure    CTenure
## 74    74 1782957 518998 171.09720  29.519510
## 7      7 1809256 476355  62.53080   7.326488
## 9      9 2113089 474725 108.99350   6.061602
## 6      6 1703140 469050 149.93590  11.351130
## 44    44 1807740 439781 182.23640 114.151900
## 2      2 1619874 424007  86.22219   6.636550
## 45    45 1602362 410149  47.64565   9.166325
## 18    18 1704826 394039 239.96980  33.774130
## 11    11 1583446 389886  44.81977   2.036961
## 47    47 1665657 387853  12.84790   6.636550

(5)2. Print the {StoreID, Sales, Profit, MTenure, CTenure} of the top 10 least profitable stores.

newdata1<-store.df[order(store.df$Profit),]
newdata1[1:10,1:5]
##    store   Sales Profit     MTenure   CTenure
## 57    57  699306 122180  24.3485700  2.956879
## 66    66  879581 146058 115.2039000  3.876797
## 41    41  744211 147327  14.9180200 11.926080
## 55    55  925744 147672   6.6703910 18.365500
## 32    32  828918 149033  36.0792600  6.636550
## 13    13  857843 152513   0.6571813  1.577002
## 54    54  811190 159792   6.6703910  3.876797
## 52    52 1073008 169201  24.1185600  3.416838
## 61    61  716589 177046  21.8184200 13.305950
## 37    37 1202917 187765  23.1985000  1.347023

(4g)Scatter plot of Profit vs. MTenure

(6).

library(car)
scatterplot(Profit ~ MTenure, data=store.df, pch = 19)

(4h)Scatter plot of Profit vs. CTenure.

library(car)
scatterplot(Profit ~ CTenure, data=store.df, pch = 19)

(4i)Construct a Correlation Matrix for all the variables in the dataset.

round(cor(store.df),2)
##            store Sales Profit MTenure CTenure   Pop  Comp Visibility
## store       1.00 -0.23  -0.20   -0.06    0.02 -0.29  0.03      -0.03
## Sales      -0.23  1.00   0.92    0.45    0.25  0.40 -0.24       0.13
## Profit     -0.20  0.92   1.00    0.44    0.26  0.43 -0.33       0.14
## MTenure    -0.06  0.45   0.44    1.00    0.24 -0.06  0.18       0.16
## CTenure     0.02  0.25   0.26    0.24    1.00  0.00 -0.07       0.07
## Pop        -0.29  0.40   0.43   -0.06    0.00  1.00 -0.27      -0.05
## Comp        0.03 -0.24  -0.33    0.18   -0.07 -0.27  1.00       0.03
## Visibility -0.03  0.13   0.14    0.16    0.07 -0.05  0.03       1.00
## PedCount   -0.22  0.42   0.45    0.06   -0.08  0.61 -0.15      -0.14
## Res        -0.03 -0.17  -0.16   -0.06   -0.34 -0.24  0.22       0.02
## Hours24     0.03  0.06  -0.03   -0.17    0.07 -0.22  0.13       0.05
## CrewSkill   0.05  0.16   0.16    0.10    0.26  0.28 -0.04      -0.20
## MgrSkill   -0.07  0.31   0.32    0.23    0.12  0.08  0.22       0.07
## ServQual   -0.32  0.39   0.36    0.18    0.08  0.12  0.02       0.21
##            PedCount   Res Hours24 CrewSkill MgrSkill ServQual
## store         -0.22 -0.03    0.03      0.05    -0.07    -0.32
## Sales          0.42 -0.17    0.06      0.16     0.31     0.39
## Profit         0.45 -0.16   -0.03      0.16     0.32     0.36
## MTenure        0.06 -0.06   -0.17      0.10     0.23     0.18
## CTenure       -0.08 -0.34    0.07      0.26     0.12     0.08
## Pop            0.61 -0.24   -0.22      0.28     0.08     0.12
## Comp          -0.15  0.22    0.13     -0.04     0.22     0.02
## Visibility    -0.14  0.02    0.05     -0.20     0.07     0.21
## PedCount       1.00 -0.28   -0.28      0.21     0.09    -0.01
## Res           -0.28  1.00   -0.09     -0.15    -0.03     0.09
## Hours24       -0.28 -0.09    1.00      0.11    -0.04     0.06
## CrewSkill      0.21 -0.15    0.11      1.00    -0.02    -0.03
## MgrSkill       0.09 -0.03   -0.04     -0.02     1.00     0.36
## ServQual      -0.01  0.09    0.06     -0.03     0.36     1.00

(4j)Use R to:

(9)1.Measure the correlation between Profit and MTenure.

x<-store.df[,c("MTenure")]
y<-store.df[,c("Profit")]
round(cor(x,y),2)
## [1] 0.44

(10)2.Measure the correlation between Profit and CTenure.

a<-store.df[,c("CTenure")]
b<-store.df[,c("Profit")]
round(cor(a,b),2)
## [1] 0.26

(4k)Construct the following Corrgram based on all variables in the dataset.

library(corrgram)
cols4<-colorRampPalette(c("peachpuff","lightpink","royalblue3","navyblue"))
corrgram(store.df, order=FALSE, col.regions=cols4, lower.panel=panel.shade, upper.panel=panel.pie, text.panel=panel.txt, main="Corrgram of store variables")

(1)Profit is positively correlated with Sales, MTenure, CTenure, Pop, Visibility, PedCount, CrewSkill, MgrSkill and ServQual.

(2)Profit is negatively correlated with Comp, Res and Hours24.

(3)Profit is strongly correlated with Sales, MTenure, CTenure, Pop, Comp, PedCount, Res, Hours24.

(4)Profit is weakly correlated with Visibilty, CrewSkill, MgrSkill, ServQual.

(4l)Run a:

(12)1.Pearson’s Correlation test on the correlation between Profit and MTenure.

cor.test(store.df[,"Profit"], store.df[,"MTenure"])
## 
##  Pearson's product-moment correlation
## 
## data:  store.df[, "Profit"] and store.df[, "MTenure"]
## t = 4.1731, df = 73, p-value = 8.193e-05
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.2353497 0.6055175
## sample estimates:
##       cor 
## 0.4388692

The p-value is 8.193e-05.

(13)2.Pearson’s Correlation test on the correlation between Profit and CTenure.

cor.test(store.df[,"Profit"], store.df[,"CTenure"])
## 
##  Pearson's product-moment correlation
## 
## data:  store.df[, "Profit"] and store.df[, "CTenure"]
## t = 2.2786, df = 73, p-value = 0.02562
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.03262507 0.45786339
## sample estimates:
##       cor 
## 0.2576789

The p-value is 0.02562.

(4m)Regression of Profit on {MTenure, CTenure, Comp, Pop, PedCount, Res, Hours24, Visibility}.

fit <- lm(Profit ~ MTenure + CTenure + Comp + Pop + PedCount + Res + Hours24 + Visibility)
summary(fit)
## 
## Call:
## lm(formula = Profit ~ MTenure + CTenure + Comp + Pop + PedCount + 
##     Res + Hours24 + Visibility)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -105789  -35946   -7069   33780  112390 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   7610.041  66821.994   0.114 0.909674    
## MTenure        760.993    127.086   5.988 9.72e-08 ***
## CTenure        944.978    421.687   2.241 0.028400 *  
## Comp        -25286.887   5491.937  -4.604 1.94e-05 ***
## Pop              3.667      1.466   2.501 0.014890 *  
## PedCount     34087.359   9073.196   3.757 0.000366 ***
## Res          91584.675  39231.283   2.334 0.022623 *  
## Hours24      63233.307  19641.114   3.219 0.001994 ** 
## Visibility   12625.447   9087.620   1.389 0.169411    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 56970 on 66 degrees of freedom
## Multiple R-squared:  0.6379, Adjusted R-squared:  0.594 
## F-statistic: 14.53 on 8 and 66 DF,  p-value: 5.382e-12

(4n)List the :(From (4m))

(15)1.Explanatory variable(s) whose beta-coefficients are statistically significant (p < 0.05).

summary(fit)
## 
## Call:
## lm(formula = Profit ~ MTenure + CTenure + Comp + Pop + PedCount + 
##     Res + Hours24 + Visibility)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -105789  -35946   -7069   33780  112390 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   7610.041  66821.994   0.114 0.909674    
## MTenure        760.993    127.086   5.988 9.72e-08 ***
## CTenure        944.978    421.687   2.241 0.028400 *  
## Comp        -25286.887   5491.937  -4.604 1.94e-05 ***
## Pop              3.667      1.466   2.501 0.014890 *  
## PedCount     34087.359   9073.196   3.757 0.000366 ***
## Res          91584.675  39231.283   2.334 0.022623 *  
## Hours24      63233.307  19641.114   3.219 0.001994 ** 
## Visibility   12625.447   9087.620   1.389 0.169411    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 56970 on 66 degrees of freedom
## Multiple R-squared:  0.6379, Adjusted R-squared:  0.594 
## F-statistic: 14.53 on 8 and 66 DF,  p-value: 5.382e-12

The explanatory variable(s) whose beta-coefficients are statistically significant (p < 0.05) are MTenure, CTenure, Comp, Pop, PedCount, Res and Hours24.

(16)2.List the explanatory variable(s) whose beta-coefficients are not statistically significant (p > 0.05).

summary(fit)
## 
## Call:
## lm(formula = Profit ~ MTenure + CTenure + Comp + Pop + PedCount + 
##     Res + Hours24 + Visibility)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -105789  -35946   -7069   33780  112390 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   7610.041  66821.994   0.114 0.909674    
## MTenure        760.993    127.086   5.988 9.72e-08 ***
## CTenure        944.978    421.687   2.241 0.028400 *  
## Comp        -25286.887   5491.937  -4.604 1.94e-05 ***
## Pop              3.667      1.466   2.501 0.014890 *  
## PedCount     34087.359   9073.196   3.757 0.000366 ***
## Res          91584.675  39231.283   2.334 0.022623 *  
## Hours24      63233.307  19641.114   3.219 0.001994 ** 
## Visibility   12625.447   9087.620   1.389 0.169411    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 56970 on 66 degrees of freedom
## Multiple R-squared:  0.6379, Adjusted R-squared:  0.594 
## F-statistic: 14.53 on 8 and 66 DF,  p-value: 5.382e-12

The explanatory variable(s) whose beta-coefficients are not statistically significant (p < 0.05) are Visibilty.

(4o)What is expected change in the Profit at a store:(From (4m))

(17)1.If the Manager’s tenure i.e. number of months of experience with Store24, increases by one month?

coefficients(fit)
##   (Intercept)       MTenure       CTenure          Comp           Pop 
##   7610.041452    760.992734    944.978026 -25286.886662      3.666606 
##      PedCount           Res       Hours24    Visibility 
##  34087.358789  91584.675234  63233.307162  12625.447050

The expected change in the Profit at a store, if the Manager’s tenure i.e. number of months of experience with Store24, increases by one month is $ 760.993.

(18)2.If the Crew’s tenure i.e. number of months of experience with Store24, increases by one month?

coefficients(fit)
##   (Intercept)       MTenure       CTenure          Comp           Pop 
##   7610.041452    760.992734    944.978026 -25286.886662      3.666606 
##      PedCount           Res       Hours24    Visibility 
##  34087.358789  91584.675234  63233.307162  12625.447050

The expected change in the Profit at a store, if the Crew’s tenure i.e. number of months of experience with Store24, increases by one month is $ 944.978

(4p)Executive Summary

Objective:

To find out the impact on Profit and Sales in various Store24 stores due to various factors and variables like tenure, skill, population etc.

Problem and Summary:

The executives of store24 are trying to figure out whether:

  1. How store-level employee retention can be increased?

  2. What is the effect of Manager and Crew Tenure on profit in stores?

  3. What are the strategies to increase Tenure?

  4. Are there any other factors that have an financial impact on sales and profit besides tenure?

Analysis and Observation

  1. A corrgram was generated, in which dark blue color and hashing that goes from lower left to upper right represent a strong positive correlation between Profit and {MTenure, CTenure, Pop and PedCount} cells.

  2. Conversely, a red color and hashing that goes from the upper left to the lower right represent a strong negative correlation between Profit and {Comp, Res, Hours24} cells.

  3. Correlation test for profit and MTenure had p-value=8.193e-05.

  4. Correlation test for profit and MTenure had p-value=0.02562.

  5. Regression of Profit on {MTenure, CTenure Comp, Pop, PedCount, Res, Hours24, Visibility} had p-values < 0.05 for {MTenure, CTenure Comp, Pop, PedCount, Res, Hours24} and p > 0.05 for {Visibilty}

  6. Multiple R-squared: 0.6379, Adjusted R-squared: 0.594

  7. F-statistic: 14.53 on 8 and 66 DF, p-value: 5.382e-12

Conclusions and Inferences

  1. There exists a strong positive correlation between Profit and {MTenure, CTenure, Pop and PedCount}.

  2. There exists a strong negative correlation between Profit and {Comp, Res, Hours24}.

  3. p-value < 0.05 for Profit and MTenure correlation test, therefore we reject the Null hypothesis and there infer that Mtenure has an impact on Profit.

  4. p-value < 0.05 for Profit and CTenure correlation test, therefore we reject the Null hypothesis and there infer that Ctenure has an impact on Profit.

  5. {MTenure, Comp, PedCount}-> (* x 3) -> Strongly related; {Hours24}-> (* x 2) -> Strongly related; {CTenure, Pop, Res}-> (* x 1) -> weakly related.

  6. Multiple R-squared: 0.6379, Adjusted R-squared: 0.594 indicates that the model is good model staistically but it indicates that there are certain other independent variables that affect Profit.

  7. F-statistics p-value<0.05 indicates that the model as a whole is statistically fit and a great model.