statistics
posted by Jessica .
Health Club Schedule
The time per workout an athlete uses a stairclimberis normally distributed with a mean of 20 mins and a standard deviation of 5 min. An athlete is randomly selected. Find the probability that the athlete uses a stairclimber between 20 and 28 mins.

Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion between the Z scores.