Sales personnel at myer department store submit weekly reports listing the customer contacts made the week. A sample if 71 weekly reports showed a sample mean of 21 customer contact per week.the sample standard deviation was 6.1. A. Develop a 90% confidence interval for the population mean number of weekly customer contacts for the sales personnel. B. Develop a 95% confidence interval for the population mean number of weekly customer contacts for the sales personnel. C. What happen to the margin of errors as the confidence from 90% to 95%