Exercise 3: Correlations and t-tests

1. Test the correlation between workload and burnout.
2. Report the correlation, confidence interval, and p-value.
3. Compare performance between training groups with an independent t-test.
4. Calculate and report a standardized effect size.
5. Using training_experiment.csv, test whether post-scores differ between groups.
6. Run a paired t-test comparing pre- and post-score for the training group.
7. Explain why statistical significance is not the same as practical importance.