According to Nielsen//NetRatings, the average visitor to the American Greetings website spends 11.85 minutes at the site.
Assuming this finding to be based on a simple random sample of 20 visitors to the site, with a sample standard deviation of s = 3.0 minutes, and from a population of visiting times that is approximately normally distributed, construct and interpret the 98% confidence interval for the population mean.
Given this confidence interval, would it seem very unusual if another sample of this size were to have a mean visiting time of 13.0 minutes?