Question: In establishing warranties on HDTV sets, the manufacturer wants to set the limits so that

few will need repair at manufacturer expense. On the other hand, the warranty period must

be long enough to make the purchase attractive to the buyer. For a new HDTV the mean

number of months until repairs are needed is 36.84 with a standard deviation of 3.34

months. Where should the warranty limits be set so that only 10 percent of the HDTVs need

repairs at the manufacturer’s expense?