Suppose that a category of world class runners are known to run a marathon (26 miles) in an average of 141 minutes with a standard deviation of 12 minutes. Consider 49 of the races. Let X = the average of the 49 races.

Give the distribution of X.

Find the probability that the average of the sample will be between 139 and 142 minutes in these 49 marathons. (Round your answer to four decimal places.)

Find the 80th percentile for the average of these 49 marathons. (Round your answer to two decimal places.) ____min

Find the median of the average running times. ____min