Question

A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful only if the average time spent on a delivery does not exceed 31 minutes. The owner has randomly selected 15 customers and delivered pizzas to their homes in order to test whether the mean delivery time actually exceeds 31 minutes. The average delivery time was 32 minutes with a standard deviation of 3.48 minutes. Should the restaurant offer pizza delivery? Use 0.05 level of significance.

1.Specify the null and alternative hypothesis.

2.Specify the rejection region.

3.Calculate the test statistic.

4.State your decision and conclusion.

Answer 1

1:

Hypotheses are:

2:

Here we have

Degree of freedom: df=n-1=14

Test is right tailed so critical value of t is : 1.7613

Rejection region:

If t >1.7613, reject H0

3:

4:

Since t does not lie in the rejection region so we fail to reject the null hypothesis.

That is we cannot conclude that the mean delivery time actually exceeds 31 minutes.