6. The mean, of the times it takes a lab technician to perform a certain task is of interest.

The lab technician was observed on sixteen different occasions, and the average time

was 4.3 minutes with the standard deviation 0.6 minute. Assume the times are normally

distributed.

(a) Find a one sided 95% confidence interval with an upper bound for the mean time.

(b) Find a 95% prediction interval on the next time to be measured.