10. Advanced Placement (AP) exams are graded on a scale of 1 (low) to 5 (high). The College Board reported that the distributions of scores on the AP Statistics Exam in 2009 was as follows: X 1 P(x) 0.34 2 0.25 3 4 5 0.18 0.16 0.07 a) A score of 3 or higher is generally needed for college credit. What is the probability of receiving a 3 or higher? b) Find the mean and the standard deviation of the AP scores.