The mean water temperature downstream from a discharge pipe at a power plant cooling tower should be no more than 100°f. past experience has indicated that the (population) standard deviation of temperature is 2°f. the water temperature is measured on nine randomly chosen days, and the average temperature is found to be 98°f. if you were to do a hypothesis test using the data from this problem to test the hypothesis that the population mean temperature is 97 degrees f, which test statistic would you need to use?