At one school,the average amount of time that tenth-graders spend watching television each week is 21.6 hours.The principal introduces a campaign to encourage the students to watch less television.One year later,the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased from the previous mean of 21.6 hours.

Question

Quizplus · Accepted Answer

The alternative hypothesis would be that the average amount of time spent watching television per week has decreased, which means we are interested in whether the sample mean is significantly lower than the previous population mean of 21.6 hours. Therefore, we need a lower-tailed hypothesis test.

At One School,the Average Amount of Time That Tenth-Graders Spend