Scores on a recent national statistics exam were normally distributed with a mean of 62 and a standard deviation of 4.
a. What is the probability that a randomly selected exam will have a score of at least 55?
b. What percentage of exams will have a score of 74?
c. What percentage of exams will have scores between 56 and 72?
d. What percentage of exams will have scores less than 66?
e. If the bottom 1% of students received failing scores, what is the highest failing score?