Accrotime is a company that manufactures quartzcrystal watches. Accrotime researchers have shown that the watches have an average life of 28 months before certain electronic componentsdeteriorate, causing the watch to become unreliable. The standard deviation of watch lifetimes is 5 months, and the distribution of lifetimes is normal.






if Acro time does not want to make refunds for more than 12% of the watches it makes how long should the guarantee period be to the nearest month

if acro time guarantees a full refund on any defective watch for two years after purchase what percentage of total production should the company expect to replace ​