A prison uses thousands of fluorescent light bulbs each year. The current brand has a mean life of 900 hours. A manufacturer claims that its new brand, which costs the same as the old brand, has a mean life of more than 900 hours.

The prision decides to test the manufacturer's claim at the alpha () = 0.05 level. Suppose 64 bulbs were tested with the following results: = 920 hours ; s=80 hours.

Does the manufacturer's claim appear correct? Remember to state all steps in hypothesis testing