22) The taxi and takeoff time for commercial jets is a random variable x with a mean of 8.5 minutes and a standard deviation of 2.5 minutes. Assume that the distribution of taxi and takeoff times is approximately normal. You may assume that the jets are lined up on a runway so that one taxies and takes off immediately after another and that they take off one at a time on a given runway. Suppose there are 36 jets on a given runway. a) What is the mean and standard deviation for the AVERAGE taxi and takeoff time for the 36 jets? b) What is the probability that for the 36 jets, total taxi and takeoff time will be 20ang 16 i) less than 320 minutes? (HINT: What would the average time be for each of the 36 que (d