11.42 In planning the processes to be incorporated into a new manufacturing facility, engineers have proposed two possible assembly procedures for one of the phases in the production sequence. Sixty of the eventual production line workers have taken part in preliminary tests, with data representing productivity

(units produced in 1 hour) for 30 workers using procedure A and 30 using procedure B. Given the data in file XR11042, use the 0.10 level of significance in determining whether the two procedures might be equally efficient. Identify and interpret the p-value for the test, then construct and interpret the 90% confidence interval for the difference between the population means.