<p>I have trouble with scoring after doing prep tests. The way to get scaled score from raw score seems varied very much among McGraw Hill's, Kaplan's and Peterson's books. For instant, on Science, I scored 34/40 questions that got 32 in McGraw Hill's but only maybe 27 in Peterson's.
So please tell me how much I need to do to get about 30-31 on each section?</p>