The annual NFL Super Bowl is the most widely watched sporting event in the United States each year. In recent years, there has been a great deal of interest in the ads that appear during the game. These ads vary in length with most lasting 30 seconds or 60 seconds. The file SuperBowlAdScore contains the ad length and ad scores from a recent Super Bowl.

a. Is there evidence of a difference in the median rating between 30-second ads and 60-second ads? (Use α = 0.05.)

b. What assumptions must you make in (a)?

c. Compare the results of (a) with those of Problem 10.11 (a) on page 360. Discuss.