Posted by Jacob on .
SAT scores are normally distributed with a mean of 1518 and a standard deviation of 325. What scores correspond to P20 and P65?
What do you mean by "P20 and P65"?
If I assume that those are percentiles, find table in the back of your statistics text labeled something like "areas under normal distribution" to find the Z scores corresponding to the proportions indicated. Insert the values into the following equation.
Z = (score-mean)/SD