1. Correlation Satisfaction level vs 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 < Than alpha (0.001) therefore we reject the Ho aka null hypothesis and say there is a positive correlation between last evaluation and satisfaction level.

Non-technical interpretation:

  • As evaluations increase, satisfaction increases slightly.

2. Correlation: Satisfaction Level vs 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 < 0.001 therefore we reject the H0 (null hypothesis) and say there is a negative correlation between satisfaction level and average monthly hours.

Non-technical interpretation

  • As average monthly hours increase, employee satisfaction decreases slightly.

3. Correlation: Average Monthly Hours vs Last Evaluation

## 
##  Pearson's product-moment correlation
## 
## data:  hr$average_montly_hours and hr$last_evaluation
## t = 44.237, df = 14997, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.3255078 0.3538218
## sample estimates:
##       cor 
## 0.3397418

Technical interpretation:

  • The p-value < 0.001 therefore we reject the H0 (null hypothesis) and say there is a positive correlation between average monthly hours and last evaluation.

Non-technical interpretation:

  • Employees who work more average monthly hours tend to have slightly higher evaluation scores.

4. Correlation: Satisfaction Level vs Time Spent with Company

## 
##  Pearson's product-moment correlation
## 
## data:  hr$satisfaction_level and hr$time_spend_company
## t = -12.416, df = 14997, p-value < 2.2e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  -0.11668153 -0.08499948
## sample estimates:
##        cor 
## -0.1008661

Technical interpretation:

  • The p-value < 0.001 therefore we reject the H0 (null hypothesis) and say there is a negative correlation between satisfaction level and time spent with the company.

Non-technical interpretation:

  • Employees who have been at the company longer tend to be slightly less satisfied.