Question 1: Satisfaction by 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 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 Interpretation:

  • We reject the Ho because the p-value < alpha (0.001) meaning that there is a difference in means of satisfaction_level between those that stayed vs. those that left

Non technical Interpretation:

  • Employees with lower satisfaction are more likely to leave