Question

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?

Answer 1

Actually in this case we will make use of the z test statistic. In which we calculate for the z score and then use the standard normal distribution tables to find for the P value at the calculate z score.

 

z = (x – u) / s

z = (97 – 98) / 2

z = -0.5

 

The z value should be greater than 1.65 to for the null hypothesis to be accepted. Hence rejected.