Posted by dw on Monday, March 5, 2012 at 11:27pm.
The average middledistance runner at a local high school runs the mile in 4.5 minutes, with a standard deviation of 0.3 minute. Find the percentage of a runners that will run the mile in less than 4 minutes?

statistics  PsyDAG, Wednesday, March 7, 2012 at 6:07pm
Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.