In research on cell phone use by teenagers it was found that the average time for a call was at least 15 minutes. Social psychologists feel that this study understated the time. To determine this claim, cell phone bills for 15 teenagers were evaluated. On average, the time spent was 18.5 minutes per call with a sample standard deviation of four minutes (assume a normal distribution) .
-The null and alternative hypotheses to test whether the original research claim is valid is _____.

Question

Quizplus · Accepted Answer

The null hypothesis (H0) should represent the original claim or the status quo, which is that the average time for a call is at least 15 minutes (? ? 15). The alternative hypothesis (Ha) should represent the claim to be tested, which in this case is that the study understated the time, suggesting that the average time is greater than 15 minutes (? > 15).

In Research on Cell Phone Use by Teenagers It Was