A major television manufacturer has determined that its 40-inch LED televisions have a mean service life that can be modeled by a normal distribution with a mean of six years and a standard deviation of one-half year.
a. What probability can you assign to service lives of at least (1) Five years? (2) Six years? (3) Seven and one-half years?
b If the manufactuerer offers service contracts of four years on these televisions what percentage can be expected to fail from wear-out during the service period?
c. What service life the manufacturer must specify, so that at least .9772 of the products would not be in need of warranty service?