One of the top-selling video games is Call of Duty:

Black Ops. While prices vary widely depending on store or website, the suggested retail price for this video game is $59.95. The file titled Black Ops contains a random sample of the retail prices paid for Call of Duty: Black Ops.

a. Calculate the sample mean and standard deviation of retail prices paid for Call of Duty: Black Ops.

b. To determine if the average retail price has fallen, assume the population mean is $59.95 and calculate the probability that a sample of size 200 would result in a sample mean no larger than the one calculated in part

a. Assume that the sample standard deviation is representative of the population standard deviation.

c. In part

b, you used $59.95 as the population mean.

Calculate the probability required in part b assuming that the population mean is $59.50.

d. On the basis of your calculations in parts b and c, does it seem likely that the average retail price for Call of Duty: Black Ops has decreased? Explain.