The average monthly electricity use per household in the USA is 910 kWh. A local util- ity company wants to know whether the average use within the population it serves exceeds the national average. In a random sample of 100 households the average monthly electricity use was 920 kWh, with a sample standard deviation 50 kWh.

a. Use a one-sided test to decide whether the average electricity use within the local popu- lation exceeds the national average. Select the significance level = .05.

b. Repeat the same test as in part (a), using = .01.

c. Without calculating the p-value, what can you say about it, based on your answers to parts (a) and (b). Help: your answer should be of the form "the p-value is less than a certain number, and larger than another number". Give a reason for your answer.

d. Make a decision for the same test as above with = .1, without any calculation.

e. Make a decision for the same test as above with = .005, without any calculation.