## 
##  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 0 and group 1 is not equal to 0
## 95 percent confidence interval:
##  0.2171815 0.2362417
## sample estimates:
## mean in group 0 mean in group 1 
##       0.6668096       0.4400980

Technical: p-value < 2.2e-16, significant difference; mean satisfaction is higher for those who stayed (0.6688096) than those who left (0.4400980). Non-Technical: Employees who stayed tend to be much more satisfied with their jobs compared to those who 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 0 and group 1 is not equal to 0
## 95 percent confidence interval:
##  -0.009772224  0.004493874
## sample estimates:
## mean in group 0 mean in group 1 
##       0.7154734       0.7181126

Technical: p-value = 0.4683, not significant; means are similar (0.7154734 vs. 0.7181126). Non-Technical: Performance evaluation scores are about the same for employees who stayed and those who left.

## 
##  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 0 and group 1 is not equal to 0
## 95 percent confidence interval:
##  -10.534631  -6.183384
## sample estimates:
## mean in group 0 mean in group 1 
##        199.0602        207.4192

Technical: p-value = 5.907e-14, significant difference; mean hours are higher for those who left (207.4192) than those who stayed (199.0602). Non-Technical: Employees who left worked more hours per month on average compared to those who stayed.

## 
##  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 0 and group 1 is not equal to 0
## 95 percent confidence interval:
##  -0.5394767 -0.4534706
## sample estimates:
## mean in group 0 mean in group 1 
##        3.380032        3.876505

Technical: p-value < 2.2e-16, significant difference; mean time is higher for those who left (3.876505 years) than those who stayed (3.380032 years). Non-Technical: Employees who left had spent more years at the company on average compared to those who stayed.