Almost all medical schools in the United States require students to take the Medical College Admission Test (MCAT). The exam is composed of three multiple-choice sections (Physical Sciences, Verbal Reasoning, and Biological Sciences). The score on each section is converted to a 15-point scale so that your total score has a maximum value of 45. The total scores follow a Normal distribution, and suppose that in a certain year the mean was 25.4 with a standard deviation of 6.5. There is little change in the distribution of scores from year to year.

(a) What percent (0.01) of students taking the MCAT had a score over 31?

%.

(b) What percent (0.01) of students had scores between 19 and 25?