Chapter 8.6, Problem 9E

WARRANTIES The general manager of the service department of MCA Television has estimated that the time that elapses between the dates of purchase and the dates on the 50-in. plasma TVs manufactured by the company first require service is normally distributed with a mean of 22 months and a standard deviation of 4 months. If the company gives a 1-year warranty on parts and labor for these TVs, determine the percentage of these TVs manufactured and sold by the company that will require service before the warranty period runs out.