Suppose that a category of world class runners are known to run a marathon (26 miles) in an average of 149 minutes with a standard deviation of 13...

Suppose that a category of world class runners are known to run a marathon (26 miles) in an average of 149 minutes with a standard deviation of 13 minutes. Consider 49 of the races.

Let X= the average of the 49 races.

Find the 60th percentile for the average of these 49 marathons.