Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the night shift than on the day shift. The mean number of units produced by a sample of 54 day-shift workers was 341. The mean number of units produced by a sample of 60 night-shift workers was 349. Assume the population standard deviation of the number of units produced on the day shift is 23 and on the night shift is 28. Using the 0.05 significance level, is the number of units produced on the night shift larger?