A copy shop records that in n = 64 cases, the cartridge for the copy machine lasted an average of 18300 copies with a standard deviation of 2800 copies. Assume that the population is normal.

(a) (10 points) Conduct a test of hypotheses with the intent of showing that the mean number of copies is greater than 17500 copies at = 0.02 significant level. What error could you have made? Explain in the context of the problem.