The General Social Survey asked: "How many e-mails do you send in a day?" The results of 928 respondents indicate that the mean number of e-mails sent in a day is 10.4, with a standard deviation of 28.5.
(a) Given the fact that 1 standard deviation to the left of the mean results in a negative number of e-mails being sent, what shape would you expect the distribution of e-mails sent to have?
(b) Construct and interpret a 90% confidence interval for the mean number of e-mails sent per day?