For Exercises 23–35, do the following:

  1. Provide the null and alternative hypotheses.
  2. Describe the two ways a correct decision could be made in the context of the problem.
  3. Describe what a Type I error would mean in the context of the problem.
  4. Describe what a Type II error would mean in the context of the problem.

Question 9.30

30. Mobile Apps. The Nielsen organization is preparing a study to determine whether the mean number of apps used per month by iPhone and Android users has increased from 28.6, its 2014 level.