The mean length of time required to perform a certain assembly line task at Joe's Manufacturing has been established to be 15.5 minutes, with a standard deviation of 3 minutes. A random sample of 9 employees are taught a new method. After a training period, the average time these 9 employees take to perform the same task is 13.5 minutes. The plant manager would like to be at least 98% sure before switching any more employees to the new, perhaps faster method and consults you for advice. Do these results provide sufficient evidence to indicate that the new method is faster than the old? Use the critical value approach to develop and test appropriate hypotheses concerning this situation. What would you advise the manager under these circumstances?