A sample of 352 subscribers to Wired magazine shows the mean time spent using the Internet is 18.4 hours per week, with a sample standard deviation of 6.8 hours. Find the 95% confidence interval for...

A sample of 352 subscribers to Wired magazine shows the mean time spent using the Internet is 18.4 hours per week, with a sample standard deviation of 6.8 hours. Find the 95% confidence interval for the mean time Wired subscribers spend on the Internet.