Most binomial probability calculations required in these exercises can be done by using Table C or the Normal approximation. Your instructor may request that you use the binomial probability formula or software. In exercises requiring the Normal approximation, you should use the continuity correction if you studied that topic.

Question 5.27

5.27 More on paying for music downloads.

Consider the settings of Exercises 5.24 and 5.26.

  1. Using the 75% rate of the Canadian teenagers, what is the smallest number out of U.S. teenagers such that is no larger than 0.05? You might consider or fewer students as evidence that the rate in your sample is lower than the 75% rate of the Canadian teenagers.
  2. Now, using the 60% rate of the U.S. teenagers and your answer to part (a), what is ? This represents the chance of obtaining enough evidence with your sample to conclude that the U.S. rate is less than the Canadian rate.

5.27

(a) . (b) 0.2131.