2. A study involving stress is done on a college campus among the students. The stress scores follow
normal distribution with the mean score of 2.25 and the standard deviation of 1.2. Using a sample of 75
students, find:
a. The probability that the average stress score for the 75 students is less than 2.
b. The 90th percentile for the average stress score for the 75 students.
c. The probability that the total of the 75 stress scores is less than 200.