mbadean.R

library(readxl)
mbadean <- read_excel("C:/Users/j.k/Desktop/New folder/mbadean.xls")
View(mbadean)
mean(mbadean$Salary)

## [1] 219078.3

malesalary <- mbadean[ which(mbadean$Gender=='M' & mbadean$Placement_B== 1), ]
femalesalary <- mbadean[ which(mbadean$Gender=='F' & mbadean$Placement_B== 1), ]
mean(malesalary$Salary)

## [1] 284241.9

mean(femalesalary$Salary)

## [1] 253068

x <- (malesalary$Salary)
y <- (femalesalary$Salary)
#compute one sample t- test in r 
# by defelt t, test function arguments
t.test(x, y=NULL, alternative = c("two.sided", "less", "greater"), mu = 0, paired = FALSE, var.equal = FALSE, conf.level = 0.95 )

## 
##  One Sample t-test
## 
## data:  x
## t = 41.917, df = 214, p-value < 2.2e-16
## alternative hypothesis: true mean is not equal to 0
## 95 percent confidence interval:
##  270875.6 297608.2
## sample estimates:
## mean of x 
##  284241.9

#two.sided is defult alternative
t.test(x,y)

## 
##  Welch Two Sample t-test
## 
## data:  x and y
## t = 3.0757, df = 243.03, p-value = 0.00234
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  11209.22 51138.42
## sample estimates:
## mean of x mean of y 
##  284241.9  253068.0