Mogul magazine has recently completed an analysis of its customer base. It has determined that 75% of the issues sold each month are subscriptions and the other 25% are sold at newsstands. It has also determined that the ages of its subscribers are normally distributed with a mean of 44.5 and a standard deviation of 7.42 years, whereas the ages of its newsstand customers are normally distributed with a mean of 36.1 and a standard deviation of 8.20 years
(a) Find the middle 80% range (i.e. range that is symmetrical about the mean) for the age of its subscribers.rs.
(b) What proportion of Mogul's newsstand customers have ages in the range computed above?
(c) What proportion of all of Mogul's customers have ages in the range given in (a