4.
a. Use the Kruskal-Wallis procedure to test whether the different quiz conditions (last question easy, moderate, difficult, or impossible) had a significant effect on postquiz anxiety scores. Regardless of the significance of your test, perform all of the possible pairwise comparisons as rank-sum tests. Which of these pairwise tests would be significant after a Bonferroni adjustment of your alpha for each comparison?

b. Repeat part (a) for the postquiz heart rates.