WORKING DIRECTORY getwd()

LOADING THE DATA INTO store.df

store.df = read.csv("StoreData.csv")

STRUCTURE OF THE DATA

str(store.df)
## 'data.frame':    2080 obs. of  10 variables:
##  $ storeNum: int  101 101 101 101 101 101 101 101 101 101 ...
##  $ Year    : int  1 1 1 1 1 1 1 1 1 1 ...
##  $ Week    : int  1 2 3 4 5 6 7 8 9 10 ...
##  $ p1sales : int  127 137 156 117 138 115 116 106 116 145 ...
##  $ p2sales : int  106 105 97 106 100 127 90 126 94 91 ...
##  $ p1price : num  2.29 2.49 2.99 2.99 2.49 2.79 2.99 2.99 2.29 2.49 ...
##  $ p2price : num  2.29 2.49 2.99 3.19 2.59 2.49 3.19 2.29 2.29 2.99 ...
##  $ p1prom  : int  0 0 1 0 0 0 0 0 0 0 ...
##  $ p2prom  : int  0 0 0 0 1 0 0 0 0 0 ...
##  $ country : Factor w/ 7 levels "AU","BR","CN",..: 7 7 7 7 7 7 7 7 7 7 ...

QUESTION 1 1a.Write R code to show the total number of rows and columns present in the data frame store.df?

dim(store.df)
## [1] 2080   10

Number of rows 2080 & Number of columns 10 1b.Write R code to list the names of the column present in the data frame store.df?

names(store.df)
##  [1] "storeNum" "Year"     "Week"     "p1sales"  "p2sales"  "p1price" 
##  [7] "p2price"  "p1prom"   "p2prom"   "country"

QUESTION 2 2a.Write R code to output the data types of the different columns?

str(store.df)
## 'data.frame':    2080 obs. of  10 variables:
##  $ storeNum: int  101 101 101 101 101 101 101 101 101 101 ...
##  $ Year    : int  1 1 1 1 1 1 1 1 1 1 ...
##  $ Week    : int  1 2 3 4 5 6 7 8 9 10 ...
##  $ p1sales : int  127 137 156 117 138 115 116 106 116 145 ...
##  $ p2sales : int  106 105 97 106 100 127 90 126 94 91 ...
##  $ p1price : num  2.29 2.49 2.99 2.99 2.49 2.79 2.99 2.99 2.29 2.49 ...
##  $ p2price : num  2.29 2.49 2.99 3.19 2.59 2.49 3.19 2.29 2.29 2.99 ...
##  $ p1prom  : int  0 0 1 0 0 0 0 0 0 0 ...
##  $ p2prom  : int  0 0 0 0 1 0 0 0 0 0 ...
##  $ country : Factor w/ 7 levels "AU","BR","CN",..: 7 7 7 7 7 7 7 7 7 7 ...

2b.Write R code to convert the data types of the columns {Year, p1prom, p2prom, country} into factor variables?

store.df$Year = as.factor(store.df$Year)
store.df$p1prom = as.factor(store.df$p1prom)
store.df$p2prom = as.factor(store.df$p2prom)
store.df$p2prom = as.factor(store.df$p2prom)

2c. Write R code to verify the conversions done in Q2b?

is.factor(store.df$Year)
## [1] TRUE
is.factor(store.df$p1prom)
## [1] TRUE
is.factor(store.df$p2prom)
## [1] TRUE
is.factor(store.df$country)
## [1] TRUE

QUESTION 3 3a. Write R code to generate the summary statistics of the different variables present in the data frame store.df?

summary(store.df)
##     storeNum     Year          Week          p1sales       p2sales     
##  Min.   :101.0   1:1040   Min.   : 1.00   Min.   : 73   Min.   : 51.0  
##  1st Qu.:105.8   2:1040   1st Qu.:13.75   1st Qu.:113   1st Qu.: 84.0  
##  Median :110.5            Median :26.50   Median :129   Median : 96.0  
##  Mean   :110.5            Mean   :26.50   Mean   :133   Mean   :100.2  
##  3rd Qu.:115.2            3rd Qu.:39.25   3rd Qu.:150   3rd Qu.:113.0  
##  Max.   :120.0            Max.   :52.00   Max.   :263   Max.   :225.0  
##                                                                        
##     p1price         p2price     p1prom   p2prom   country 
##  Min.   :2.190   Min.   :2.29   0:1872   0:1792   AU:104  
##  1st Qu.:2.290   1st Qu.:2.49   1: 208   1: 288   BR:208  
##  Median :2.490   Median :2.59                     CN:208  
##  Mean   :2.544   Mean   :2.70                     DE:520  
##  3rd Qu.:2.790   3rd Qu.:2.99                     GB:312  
##  Max.   :2.990   Max.   :3.19                     JP:416  
##                                                   US:312

Q3b. Write R code to generate the following table using the describe() function from the psych package in R?

psych::describe(store.df)
##          vars    n   mean    sd median trimmed   mad    min    max range
## storeNum    1 2080 110.50  5.77 110.50  110.50  7.41 101.00 120.00  19.0
## Year*       2 2080   1.50  0.50   1.50    1.50  0.74   1.00   2.00   1.0
## Week        3 2080  26.50 15.01  26.50   26.50 19.27   1.00  52.00  51.0
## p1sales     4 2080 133.05 28.37 129.00  131.08 26.69  73.00 263.00 190.0
## p2sales     5 2080 100.16 24.42  96.00   98.05 22.24  51.00 225.00 174.0
## p1price     6 2080   2.54  0.29   2.49    2.53  0.44   2.19   2.99   0.8
## p2price     7 2080   2.70  0.33   2.59    2.69  0.44   2.29   3.19   0.9
## p1prom*     8 2080   1.10  0.30   1.00    1.00  0.00   1.00   2.00   1.0
## p2prom*     9 2080   1.14  0.35   1.00    1.05  0.00   1.00   2.00   1.0
## country*   10 2080   4.55  1.72   4.50    4.62  2.22   1.00   7.00   6.0
##           skew kurtosis   se
## storeNum  0.00    -1.21 0.13
## Year*     0.00    -2.00 0.01
## Week      0.00    -1.20 0.33
## p1sales   0.74     0.66 0.62
## p2sales   0.99     1.51 0.54
## p1price   0.28    -1.44 0.01
## p2price   0.32    -1.40 0.01
## p1prom*   2.66     5.10 0.01
## p2prom*   2.09     2.38 0.01
## country* -0.29    -0.81 0.04

QUESTION 4 4a. Break-up store.df by country. Write R code to generate the following break-ups by country?

with(store.df,table(country))
## country
##  AU  BR  CN  DE  GB  JP  US 
## 104 208 208 520 312 416 312

QUESTION 5 5a.The dataset has 2080 rows of weekly data for 20 unique store branches for two different years. For product 1 (Coke) and product 2 (Pepsi), write R code to count the number of weeks, I.When both products were under promotion?

nrow(subset(store.df, store.df$p1prom==1 & store.df$p2prom==1))
## [1] 32

II.When product 1 (Coke) was under promotion but product 2 (Pepsi) was not under promotion?

nrow(subset(store.df, store.df$p1prom==1 & store.df$p2prom==0))
## [1] 176

III.When product 1 (Coke) was not under promotion but product 2 (Pepsi) was under promotion?

nrow(subset(store.df, store.df$p1prom==0 & store.df$p2prom==1))
## [1] 256

IV.When neither product was under promotion?

nrow(subset(store.df, store.df$p1prom==0 & store.df$p2prom==0))
## [1] 1616

5b. Express Q5a as in percentages? I.When both products were under promotion?

nrow(subset(store.df, store.df$p1prom==1 & store.df$p2prom==1))*100/nrow(store.df)
## [1] 1.538462

II.When product 1 (Coke) was under promotion but product 2 (Pepsi) was not under promotion?

nrow(subset(store.df, store.df$p1prom==1 & store.df$p2prom==0))*100/nrow(store.df)
## [1] 8.461538

III.When product 1 (Coke) was not under promotion but product 2 (Pepsi) was under promotion?

nrow(subset(store.df, store.df$p1prom==0 & store.df$p2prom==1))*100/nrow(store.df)
## [1] 12.30769

IV.When neither product was under promotion?

nrow(subset(store.df, store.df$p1prom==0 & store.df$p2prom==0))*100/nrow(store.df)
## [1] 77.69231

5c. Write R code to calculate the average price of product 1 (Coke) and product 2 (Pepsi) when both were under promotion?

a= (subset(store.df, store.df$p1prom==1 & store.df$p2prom==1))
mean(a$p1price)
## [1] 2.568125
mean(a$p2price)
## [1] 2.67125

5d. Write R code to calculate the average price of product 1 (Coke) and product 2 (Pepsi) when neither of them was under promotion?

b= (subset(store.df, store.df$p1prom==0 & store.df$p2prom==0))
mean(b$p1price)
## [1] 2.543342
mean(b$p2price)
## [1] 2.700891

5e. Write R code to calculate the average price of product 1 (Coke) and product 2 (Pepsi) when only one of them was under promotion? When Product 1 was under promotion

c= (subset(store.df, store.df$p1prom==1 & store.df$p2prom==0))
mean(c$p1price)
## [1] 2.524659
mean(c$p2price)
## [1] 2.703068

When Product 2 was under promotion

d= (subset(store.df, store.df$p1prom==0 & store.df$p2prom==1))
mean(d$p1price)
## [1] 2.561484
mean(d$p2price)
## [1] 2.691953