statistics
posted by kelly on .
the mean scale score on the mathematics examination of ninth grade students in new york state was 86 with a standard deviation of 5 points. Given a student was selected at random what is the probabilty that his score was 91 or higher?

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