A microwave oven repairer says that the mean repair cost for damaged microwave ovens is less than $100. You find that a random sample of five microwave ovens has a mean repair cost of $75 and a standard deviation of $12.50. Assume the repair costs are normally distributed. Use the graphing calculator to find the following: (a) Test statistic= Round answer to four decimal places. (b) P-value= Round answer to four decimal places