15.31 Parametric or nonparametric test? For each of the following research questions, state whether a parametric or nonparametric hypothesis test is more appropriate. Explain your answers.

a. Are women more or less likely than men to be economics majors?

b. At a small company with 15 staff and one top boss, do those with a university education tend to make a different amount of money than those without one?

c. At your high school, did athletes or nonathletes tend to have higher grade-point averages?

d. At your high school, did athletes or nonathletes tend to have higher class ranks?

e. Compare car accidents in which the occupants were wearing seat belts with accidents in which the occupants were not wearing seat belts. Do seat belts seem to make a difference in the numbers of accidents that lead to no injuries, nonfatal injuries, and fatal injuries?

f. Compare car accidents in which the occupants were wearing seat belts with accidents in which the occupants were not wearing seat belts. Were those wearing seat belts driving at slower speeds, on average, than those not wearing seat belts?