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")?