1) A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1000 hours. A homeowner selects 25 bulbs and finds the mean lifetime tobe...

1)  A manufacturer claims that the mean lifetime of its fluorescent bulbs is 1000 hours. A homeowner selects 25 bulbs and finds the mean lifetime tobe 980 hours with a standard deviation of 80 hours. If a = 0.05, test the manufacturer's claim.

a  a) Give the Ho and Ha and label which is the claim

    b) give the pvalue

     c) give your final decision about the claim.