For which one of the situations described in Exercise 3 would a Kendall’s tau be appropriate?

In Exercise 3

For which one of the following situations would a Wilcoxon signed-rank test be appropriate?

a) Comparing the ratings of a new product on a five-point Likert scale by a panel of consumers with their ratings of a competitor’s product on the same scale.

b) Comparing the sweetness of a diet drink (rated from 1 to 10) as judged by a panel of teenaged tasters and a panel of adult tasters.

c) Judging whether the height of the water at high tide at a marina increases more or less consistently as the phase of the moon changes from new to full.

d) Testing whether the distributions of the ratings of a new distance-learning course were the same as rated (on the usual five-point Likert scale) by first-, second-, third-, and fourth-year students who had taken the course.

e) Estimating the association between the value of homes and their age in a community known to have a number of very expensive mansions.