posted by joey on .
How do I find a percentile if I only have the mean and sd? ie...what IQ score is associated with the 65th percentile?-mean is 100 and sd is 15. Thanks in advance :)
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion (.65) related to the Z score. Insert the values into the equation above and solve for the IQ.