QUESTION 8 Managers at an automobile manufacturing plant would like to examine the mean completion time of an assembly line operation. The past data indicate that the mean completion time is 43 minutes, but the managers have reason to believe that this value has decreased. The managers plan to perform a statistical test of that belief. After choosing a random sample of 9 assembly line completion times, the managers compute the sample mean completion time to be 40 minutes and the standard deviation to be 3 minutes. Find the 95% confidence interval for the population mean. (37.694, 42.306) (38.040, 41.960) (39.282, 40.718) (37.738, 42.262)