Researchers have estimated that office workers in Germany receive an average of 15.0 fax messages per day. Assuming this finding to be based on a simple random sample of 80 German office workers, with a sample standard deviation of s = 3.5 messages, construct and interpret the 95% 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 of 16.5 faxes?