The US energy information Association claims that the mean monthly residential electricity consumption in your town is more than 874 kilowatt hours. You want to test this claim. You find that a random sample of 64 residential customers have an average monthly electricity consumption of 905 kilowatt hours. Assume that the population standard deviation is 125 kilowatt hours. At alpha=0.05, do you have enough evidence to support the associations claim?

a. show the null and alternative hypothesis, and which is the claim

b. find the critical values and identify the rejection region on a bell curve

c. find the test statistic z

d. decide whether to reject the null or fail to reject the null

e. Interpret the decision in the context of the original claim