Sales personnel for Skillings Distributors submit weekly reports listing the customer contacts made during the week. A sample of 66 weekly reports showed a sample mean of ?% = 19.50 and a sample...

1. Sales personnel for Skillings Distributors submit weekly reports listing the customer contacts made during the week. A sample of 66 weekly reports showed a sample mean of ?% = 19.50 and a sample standard deviation of ?" = 5.20.

(a)Estimate a 95% confidence interval for the population average number of contacts, ?".

(b) Estimate a 99% confidence interval for the population variance, s X2 .