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 and group Left is not equal to 0
## 95 percent confidence interval:
##  -10.534631  -6.183384
## sample estimates:
## mean in group Stayed   mean in group Left 
##             199.0602             207.4192

Technical Interpretation

Reject the Ho, p value < 0.01, accept alternative hypothesis: there is a difference in means, where employees who left had more average monthly hours.

Non-Technical Interpretation

Employees that left worked more average hours.

Graph 1

2. Satisfaction Level vs Left

T-Test

## 
##  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 and group Left is not equal to 0
## 95 percent confidence interval:
##  0.2171815 0.2362417
## sample estimates:
## mean in group Stayed   mean in group Left 
##            0.6668096            0.4400980

Technical Interpretation

Reject the Ho, p value < 0.01, accept alternative hypothesis: there is a difference in means, where employees who left had lower satisfaction levels.

Non-Technical Interpretation

Employees that left had lower Satisfaction levels.

Graph 2

3. Last Evaluation vs Left

## 
##  Welch Two Sample t-test
## 
## data:  hr$last_evaluation by hr$left
## t = -0.72534, df = 5154.9, p-value = 0.4683
## alternative hypothesis: true difference in means between group Stayed and group Left is not equal to 0
## 95 percent confidence interval:
##  -0.009772224  0.004493874
## sample estimates:
## mean in group Stayed   mean in group Left 
##            0.7154734            0.7181126

Technical Interpretation

Accept the Ho, p value > 0.01, There is no significant difference in last evaluation score mean between employees who left and those that stayed.

Non-Technical Interpretation

Employees that stayed averaged the same evaluation score as those who left.

Graph 3

4. Time Spent at Company vs Left

## 
##  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 and group Left is not equal to 0
## 95 percent confidence interval:
##  -0.5394767 -0.4534706
## sample estimates:
## mean in group Stayed   mean in group Left 
##             3.380032             3.876505

Technical Interpretation

Reject the Ho, p value < 0.01, accept alternative hypothesis: there is a difference in means, where employees who left had more time spent at company.

Non-Technical Interpretation

Employees who left worked at the company for a longer period of time.

Graph 4