# The data set used
SmokeBan <- read.csv("https://vincentarelbundock.github.io/Rdatasets/csv/AER/SmokeBan.csv", header = TRUE)

# CREATE A NEW DATA FRAME WITH COLUMNS AND ROWS

# Creating and displaying a new data frame called "Smokers50AndUnder".
Smokers50AndUnder <- subset(SmokeBan,smoker=="yes" & age<= 50,select=c(gender,ban,age))

#Displaying the first 20 records
head(Smokers50AndUnder,20)

##    gender ban age
## 1  female yes  41
## 2  female yes  44
## 4  female  no  29
## 7  female yes  47
## 8    male  no  36
## 19 female yes  28
## 20   male yes  24
## 21   male yes  39
## 25   male yes  31
## 26 female  no  33
## 29   male  no  24
## 34   male  no  48
## 40 female  no  32
## 42   male  no  27
## 43 female yes  30
## 45 female  no  18
## 47 female yes  48
## 50   male yes  41
## 56 female yes  46
## 80   male yes  43

# ADD A NEW COLUMN TO THE DATA FRAME. 

# Adding the years_smoking column. This column denotes the number of years an employee has been smoking. The values for the new column will be randomly generated up to 25 years.
Smokers50AndUnder$years_smoked<-sample(1:25, size = 2054, replace = T)

#Displaying the first 20 records
head(Smokers50AndUnder,20)

##    gender ban age years_smoked
## 1  female yes  41            2
## 2  female yes  44            5
## 4  female  no  29           19
## 7  female yes  47           16
## 8    male  no  36           17
## 19 female yes  28           11
## 20   male yes  24           11
## 21   male yes  39            4
## 25   male yes  31           22
## 26 female  no  33           20
## 29   male  no  24           25
## 34   male  no  48            4
## 40 female  no  32           17
## 42   male  no  27           11
## 43 female yes  30            4
## 45 female  no  18           11
## 47 female yes  48           19
## 50   male yes  41           17
## 56 female yes  46           22
## 80   male yes  43           17

# CREATING S SUBSET OF THE DATA FRAME. 

# for all smokers who are over 40 add a ban.
Smokers50AndUnder$ban[Smokers50AndUnder$age > 40]<-'yes'

#Displaying the first 20 records
head(Smokers50AndUnder,20)

##    gender ban age years_smoked
## 1  female yes  41            2
## 2  female yes  44            5
## 4  female  no  29           19
## 7  female yes  47           16
## 8    male  no  36           17
## 19 female yes  28           11
## 20   male yes  24           11
## 21   male yes  39            4
## 25   male yes  31           22
## 26 female  no  33           20
## 29   male  no  24           25
## 34   male yes  48            4
## 40 female  no  32           17
## 42   male  no  27           11
## 43 female yes  30            4
## 45 female  no  18           11
## 47 female yes  48           19
## 50   male yes  41           17
## 56 female yes  46           22
## 80   male yes  43           17