At one school, the average amount of time that spend watching television each week is 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

Step-by-step explanation:

Hypothesis testing allows to identify a event test. The correct order of the steps of a hypothesis test is given following  

1. Determine the null and alternative hypothesis.

2. Select a sample and compute the z - score for the sample mean.

3. Determine the probability at which you will conclude that the sample outcome is very unlikely.

4. Make a decision about the unknown population.

These steps are performed in the given sequence to test a hypothesis.

The principal tests the hypothesis with a mean of 21.6 hours for the determination of average amount of time spent watching television.