The Readylite Company produces a flashlight in which product managers are trying to decide how long a warranty to issue. If the managers believe the life of the flashlight follows a normal distribution with a mean of three years and a standard deviation of six months:
a) What percentage of flashlights sold can they anticipate will be returned within the first two years?
b) What percentage of flashlights sold can they anticipate will be returned within the first three years?