A certain airline wishes to estimate the mean number of seats that are empty on flights that use 737-airplanes. There are 189 seats on a 737. To do so, the airline randomly picks n = 33 flights. For each flight, the number of empty seats is counted. The data are given below. 47, 45, 31, 38, 40, 45, 32, 29, 49, 35, 40, 29, 44, 47, 44, 34, 28, 45, 28, 42, 33, 41, 40, 34, 28, 49, 37, 39, 25, 30, 48, 33, 34 Remaining time: 680:40 (min:sec) Data from the sample, are saved in the Download .csv file. Distribution of Empty Seats Frequency 30 35 40 50 Number of Unoccupied Seats (a) Find the mean and the standard deviation of this sample. Use at least three decimal places in each answer. X = empty seats S = empty seats (b) To construct a confidence interval for the mean number of unoccupied seats on all flights that use 737s, what condition must you hold? A. One does not need to assume the number of unoccupied seats are normally distributed, because the sample size is sufficiently large. O B. The number of unoccupied seats are not normally distributed. O C. That the number of unoccupied seats are normally distributed O D. The number of unoccupied seats can be modeled by the Binomial distribution. (c) Find a 91% confidence interval for A, the mean number of empty seats on this airline's flights that use 737s. Use at least three decimal points for your lower and upper bounds. Lower Bound = empty seats Upper Bound = empty seats