Customers were waiting in line too long so data was collected. The mean time was 28 minutes. One month later a sample of 127 customers was selected....

Customers were waiting in line too long so data was collected. The mean time was 28 minutes. One month later a sample of 127 customers was selected. The mean wait time recorded was 26.9 minutes and the S.D. of the sampling was 8 minutes. Shall we reject the null hypothesis of the mean >/= 28 in favor of the alternate hypothesis, mean < 28, at a 2% significance level.