1. average monthly hours vs left

t- test

## 
##  Welch Two Sample t-test
## 
## data:  hr$average_montly_hours by hr$left
## t = -7.5323, df = 4875.1, p-value = 5.907e-14
## alternative hypothesis: true difference in means between group Stayed, Left1 and group Stayed, Left2 is not equal to 0
## 95 percent confidence interval:
##  -10.534631  -6.183384
## sample estimates:
## mean in group Stayed, Left1 mean in group Stayed, Left2 
##                    199.0602                    207.4192

Technical Interpretation

reject the Ho, p- value <0.01, there is a difference in means, where eployees who left had more average monthly hours

Non- technical interpretation

employees that left worked more hours

Graph

2. T- test last evaluation vs left

## 
##  Welch Two Sample t-test
## 
## data:  hr$satisfaction_level by hr$left
## t = 46.636, df = 5167, p-value < 2.2e-16
## alternative hypothesis: true difference in means between group Stayed, Left1 and group Stayed, Left2 is not equal to 0
## 95 percent confidence interval:
##  0.2171815 0.2362417
## sample estimates:
## mean in group Stayed, Left1 mean in group Stayed, Left2 
##                   0.6668096                   0.4400980

Technical Interpretation

Fail to reject the Ho, p- value >0.01, there is no difference in mean, where eployees who left did not have a significant difference in last evaluation scores

Non- technical interpretation

There is no differnece in last evaluation scores between employees who stayed versus employees who left.

3. T test satisfaction level based on those who left

## 
##  Welch Two Sample t-test
## 
## data:  hr$satisfaction_level by hr$left
## t = 46.636, df = 5167, p-value < 2.2e-16
## alternative hypothesis: true difference in means between group Stayed, Left1 and group Stayed, Left2 is not equal to 0
## 95 percent confidence interval:
##  0.2171815 0.2362417
## sample estimates:
## mean in group Stayed, Left1 mean in group Stayed, Left2 
##                   0.6668096                   0.4400980

Technical Interpretation

reject the Ho, p- value <0.01, there is a difference in means, where eployees who left reported lower satisfaction levels.

Non- technical interpretation

employees that left were less satisfied

4. T-test left vs time spent at company

## 
##  Welch Two Sample t-test
## 
## data:  hr$time_spend_company by hr$left
## t = -22.631, df = 9625.6, p-value < 2.2e-16
## alternative hypothesis: true difference in means between group Stayed, Left1 and group Stayed, Left2 is not equal to 0
## 95 percent confidence interval:
##  -0.5394767 -0.4534706
## sample estimates:
## mean in group Stayed, Left1 mean in group Stayed, Left2 
##                    3.380032                    3.876505

Technical Interpretation

reject the Ho, p- value <0.01, there is a difference in means, where eployees who left spent more time at the company.

Non- technical interpretation

employees that left spent more time at the company