There are five accounting exams. Bob’s typical score on each
exam is a random variable with a mean of 80 and a standard deviation of 5. His
final grade is based on the sum of his exam scores. (a) Find the mean and
standard deviation of Bob’s point total assuming his performances on exams are
independent of each other. (b) By the Empirical Rule (see Chapter 4) would you
expect that Bob would earn at least 450 points (the required total for an “A”)?
