The life spans of batteries is known to be normally distributed, with a mean of 2250 hours and a standard deviation of 144 hours. a. Find the probability of a battery chosen at random will have a life...

The life spans of batteries is known to be normally distributed, with a mean of 2250 hours and a standard deviation of 144 hours.

a. Find the probability of a battery chosen at random will have a life span less than 1980 hours.__________________
 (Answer with 5 decimals)

b. The percent of batteries that will have a life span that over 2095 hours?  ______________________
(Answer with 5 decimals)