1️⃣ T-Test: Satisfaction Level by Attrition

Perform the 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 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 (p-value)

The p-value is less than 0.05, meaning the difference in satisfaction levels between employees who left and those who stayed is statistically significant.

Non-Technical Interpretation

Employees who leave tend to have lower satisfaction levels.

Visualization

2️⃣ T-Test: Average Monthly Hours by Attrition

Perform the 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 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 Interpretation (p-value)

The p-value is less than 0.05, indicating a statistically significant difference in average monthly hours between employees who left and those who stayed.

Non-Technical Interpretation

Employees who leave tend to work more hours.

Visualization

3️⃣ T-Test: Number of Projects by Attrition

Perform the t-test

## 
##  Welch Two Sample t-test
## 
## data:  hr$number_project by hr$left
## t = -2.1663, df = 4236.5, p-value = 0.03034
## alternative hypothesis: true difference in means between group 0 and group 1 is not equal to 0
## 95 percent confidence interval:
##  -0.131136535 -0.006540119
## sample estimates:
## mean in group 0 mean in group 1 
##        3.786664        3.855503

Technical Interpretation (p-value)

The p-value is less than 0.05, showing a statistically significant difference in number of projects between employees who left and those who stayed.

Non-Technical Interpretation

Employees who leave tend to have more projects.

Visualization

4️⃣ T-Test: Time Spent at Company by Attrition

Perform the t-test

## 
##  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 Interpretation (p-value)

The p-value is less than 0.05, indicating a statistically significant difference in time spent at the company between employees who left and those who stayed.

Non-Technical Interpretation

Employees who leave tend to have spent more time at the company.

Visualization