Accrotime is a manufacturer of quartz crystal Watches. Accrotime researchers have shown that the watches have an average life of 30 months before certain electronic components
deteriorate, causing the watch to become unreliable. The standard deviation of watch lifetimes is 5 months, and the distribution of lifetimes is normal
(a) If Accrotime guarantees a full refund on any defective watch for 2 years after purchase, what percentage of total production will the company expect to replace? (Round your
answer to two decimal places.)
%
(b) If Accrotime does not want to make refunds on more than 6% of the watches it makes, how long should the guarantee period be to the nearest month)?
months