How large is this effect?

Question

A new company has made the claim that its test preparation will improve SAT scores by 50 points. A skeptical educational psychologist has decided to test this theory, and has enlisted 40 students who are willing to participate in this program. Assume the standard SAT mean of 500 with a standard deviation of 75. 

Answer 1

This question is missing some information. You would need to know their scores before the test preparation and after the preparation, and compare their average increase in score across all 40 students. It would require a paired t-test to analyze the results.