1. Correlation between Satisfaction Level and Last Evaluation

## 
##  Pearson's product-moment correlation
## 
## data:  hr$satisfaction_level and hr$last_evaluation
## t = 12.933, df = 14997, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.08916727 0.12082195
## sample estimates:
##       cor 
## 0.1050212
Technical Interpretation
  • The p-value is very small (p<0.05), which means the correlation between satisfaction level and last evaluation is statistically significant.
  • The correlation coefficient is small and positive so it has a weak positive correlation. As satisfaction increases, evaluation scores tend to rise slightly.
Non-Technical Interpretation
  • Employees who are more satisfied with their jobs tend to receive slightly higher performance evaluations.
Graph

2. Correlation between Average Monthly Hours and Number of Projects

## 
##  Pearson's product-moment correlation
## 
## data:  hr$average_montly_hours and hr$number_project
## t = 56.219, df = 14997, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.4039037 0.4303411
## sample estimates:
##       cor 
## 0.4172106
Technical Interpretation
  • The p-value is small (p<0.05), so the correlation is statistically significant.
  • The correlation coefficient slightly small and positive so it has a moderate positive correlation. Employees working on more projects generally log more hours per month.
Non-Technical Interpretation
  • The more projects an employee works on, the more hours they tend to spend at work each month.
Graph

3. Correlation between Time Spent at Company and Last Evaluation

## 
##  Pearson's product-moment correlation
## 
## data:  hr$time_spend_company and hr$last_evaluation
## t = 16.256, df = 14997, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.1158309 0.1472844
## sample estimates:
##       cor 
## 0.1315907
Technical Interpretation
  • The p-value is small (p<0.05), meaning this correlation is statistically significant.
  • The correlation coefficient is small and positive so has a weak positive correlation. Employees with more years at the company tend to have slightly higher evaluation scores.
Non-Technical Interpretation
  • Employees who have been with the company longer usually receive somewhat higher performance evaluations.
Graph

4. Correlation between Satisfaction Level and Average Monthly Hours

## 
##  Pearson's product-moment correlation
## 
## data:  hr$satisfaction_level and hr$average_montly_hours
## t = -2.4556, df = 14997, p-value = 0.01408
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.036040356 -0.004045605
## sample estimates:
##         cor 
## -0.02004811
Technical Interpretation
  • The p-value is greater than 0.05, meaning this correlation is not statistically significant.
  • The correlation coefficient is low and negative indicating almost no relationship between satisfaction level and average monthly hours.
Non-Technical Interpretation
  • Employees’ satisfaction levels don’t seem to be related to how many hours they work each month.
Graph