statistic

A manufacturer of a particular brand of LCD TV claims that the lifetime
of the latest 19-inch LCD panel should be equal to 60,000 hours on
average. The lifetime can be assumed to be normally distributed. A
sample of 12 panels was randomly selected and the corresponding
average lifetime was found to be 62,450 hours with a standard deviation
of 4,800 hours.

aTest the manufacturer’s claim at the 0.05 level of significance.