1. Is there a difference in satisfaction level between those that left and those that stayed in the company?

Conclusion: Employees that stayed, on average, are more satisfied

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

2. Is there a difference in average monthly hours between those that left and those that stayed in the company?

Conclusion: Employees that left, on average, worked more hours than those that stayed

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

3. Is there a difference in last evaluation between those that left and those that stayed in the company?

Conclusion: An employees last evaluation has no effect on them leaving or staying

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