Let's suppose that the time it takes for High School Senior Boys in America to run 1 miles is normally distributed with population mean ( ) = 750 seconds and population standard deviation ( ) = 50 seconds.
Assume 25 randomly selected students ran the mile and we computed the average.
a) Determine the probability that this mean will be less than 755 seconds?
b) Determine the probability that this mean is less than 730 seconds?
c) Determine the probability that this mean is greater than 820 seconds?