Accrotime is a manufacturer of quartz crystal watches. Accrotimeresearchers have shown that the watches have an average life of 26months before certain electronic components deteriorate, causingthe watch to become unreliable. The standard deviation of watchlifetimes is 4 months, and the distribution of lifetimes isnormal.
(a) If Accrotime guarantees a full refund on any defective watchfor 2 years after purchase, what percentage of total productionwill the company expect to replace? (Round your answer to twodecimal places.)
(b) If Accrotime does not want to make refunds on more than 12% ofthe watches it makes, how long should the guarantee period be (tothe nearest month)?
