The iPhone battery capacity is normally distributed with a mean of 4 years and a standard deviation of 10 months.
a. What is the probability that a randomly selected battery will last more than 5 years?
b. What percentage of batteries will last between 5 and 6 years?
c. What percentage of batteries will last less than 4 years?
d. What percentage of batteries will last between 2.5 and 4.5 years?