Statisitcs
posted by Johnny .
Scores on the verbal section of the SAT have a mean of 500 and a standard deviation of 100. If someone scored at the 90th percentile, what is their SAT score?

Can someone show me how to find this equation to this problem?
Scores on the verbal section of the SAT have a mean of 500 and a standard deviation of 100. If someone scored at the 90th percentile, what is their SAT score? 
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z score related to that proportion.
Z = (scoremean)/SD
Insert the values and solve for the score.