A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 761 hours. A random sample of 25 light bulbs has a mean life of 745 hours. Assume the population is...

A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 761 hours. A random sample of 25 light bulbs has a mean life of 745 hours. Assume the population is normally distributed and the population standard deviation is 56 hours. At α=0.05​, do you have enough evidence to reject the​ manufacturer's claim? Complete parts​ (a) through​ (e).