The CEO of a large utility company believes that the average November 2015 electric bill of customers in his service area is at most $160.00. So, he randomly selects 20 households from the service area and records their November electric bills. The mean electric bill of these 20 households was $152.50 and the standard deviation of these electric bills was $8.75. Assume that electric bills for customers in this service area are normally distributed regardless of the month. Let ? = .05 and conduct the appropriate hypothesis test regarding the true average November 2015 electric bill of these utility customers.

(a) Determine the null and alternative hypotheses for this test. Identify the claim – is the claim the null hypothesis or the alternative hypothesis?

(b) Will this test be a one-tailed right, one-tailed left, or a two-tailed test? Identify the critical value(s) for this test.

(c) Compute the test statistics associated with this test.

Make your decision – do you reject H0 or fail to reject H0? Explain.

(e) State your conclusion.