Because of adverse publicity about the overbooking on American Airline flights, the public relationsdirector of the airline wants to estimate the mean number of passengers on American non-peak hourflights from Newark to Chicago during the past month. From experience, he knows that the numberof passengers on such flights is normally distributed. He has just received a random sample of 10flights with the number of passengers being as follows: 40, 55, 60, 90, 30, 50, 150, 100, 90, 80.(a) What is the estimate of the mean and standard deviation of the number of passengers on suchflights?

(b) Find a 98%-confidence interval for the mean number of passengers.