A streaming service believes that the proportion of users who watch content on a mobile device is different from 35%. The company randomly samples 160 users and finds that 44 primarily watch on mobile (). Which hypotheses are appropriate for testing the company’s belief?
- (correct answer)
Explanation: The skill here is crafting hypotheses for a one-proportion z-test in AP Statistics to examine if p differs from 0.35. The correct setup is H0: p = 0.35 and Ha: p ≠ 0.35, capturing the two-sided nature of 'different from,' as in choice A. A distractor is choice C, which uses ˆp incorrectly. Choice D uses a one-sided alternative, but 'different' requires checking both directions. For a mini-lesson, two-sided alternatives use ≠ for claims of difference or inaccuracy. Null is always equality, focused on p. Sample data tests the hypotheses but doesn't appear in them.