3. The mean score on a test (out of 80) was found to be 64.2 and the standard deviation was determined to be 3.5

a) Determine the probability that a student's score chosen at random is less than 72.

b) Determine the probability that a student's score chosen at random is greater than 72.

c) P(58< x <68) (score is between 58 and 68)