A microwave manufacturing company has just switched to a newautomated production system. Unfortunately, the new machinery hasbeen frequently failing and requiring repairs and service. Thecompany has been able to provide its customers with a completiontime of 6 days or less. To analyze whether the completion time hasincreased, the production manager took a sample of 36 jobs andfound that the sample mean completion time was 6.5 days with asample standard deviation of 1.5 days.
a) At a significance level of 0.10, test whether the completiontime has increased.
b) Find and interpret a 99% confidence interval for the meancompletion time.
