The mean length of a work week for the population of workers was reported to be 39.2 hours. Suppose that we would like to take a current sample of workers to see whether the mean length of a work week has changed from the previously reported 39.2 hours.
A. State the hypotheses that will help us determine whether a change occurred in the mean length of a work week.
B. Suppose a current sample of 112 workers provided a sample mean of 38.5 hours. Use a population standard deviation = 4.8 hours. What is the p-value?
C. At a = .05 can the null hypothesis be rejected? What is your conclusion?
D. Repeat the preceding hypothesis test using the critical value approach.