Sales personnel for a product distributor submit weekly reports listing the customer contacts made during the week. A sample of 65 weekly reports showed a sample mean of 19.5 customer contacts per week. The sample standard deviation was 5.2.

A.Find a 90% confidence interval for the population mean and interpret. (5 Marks)

B.Find a 95% confidence interval for the population mean and interpret. (5 Marks)

C.Compare the intervals between 90% and 95% confidence level. (1 Mark)

Please type yourself, not in paper.