When Juan commutes to work, the amount of time it takes him to arrive is normally distributed with a mean of 31 minutes and a standard deviation of 4.5 minutes. Using the empirical rule, what percentage of his commutes will be between 22 and 40 minutes?

Sales personnel for skillings distributors submit weekly reports listing the customer contacts made during the week. a sample of 55 weekly reports showed a sample mean of 17.5 customer contacts per week. the sample standard deviation was 5.8. provide 90% and 95% confidence intervals for the population mean number of weekly customer contacts for the sales personnel. a. 90% confidence interval, to 2 decimals b. 95% confidence interval, to 2 decimals