Exercise 3: Correlations and t-tests

Use data/training_experiment.csv and data/employee_survey.csv.

1. Calculate the correlation between workload and burnout.
2. Describe the post-score mean and SD in each experimental group.
3. Run a two-sided Welch t-test comparing post-scores.
4. Write (H_0) and (H_1) in words.
5. Suppose the directional hypothesis was pre-specified as “Training produces higher post-scores than Control.” Create explicit Training and Control vectors and run alternative = "greater".
6. Compare the one-sided and two-sided outputs. Why are they different?
7. Calculate Cohen’s (d).
8. Run a paired t-test comparing pre- and post-scores within the Training group.
9. Write a four-sentence results interpretation that distinguishes statistical evidence from managerial importance.
10. Explain why choosing the one-sided direction after seeing the data would be inappropriate.