Last year, the mean running time for a certain type of light bulb was 8.5 hours. This year, the manufacturer has introduced a change in the production method. A random sample of40 of the new light bulbs has a mean running time of 8.7 hours with a standard deviation of 0.5 hours. At the 0.05 signicance level, test the claim that the mean running time of thenew light bulbs is greater than last year's mean of 8.5 hour Required:
a. State the null and alternative hypotheses symbolically.
b. Which test procedure is appropriate to perform the required hypothesis test?
c. Compute the value of the test statistic.
d. Determine the P-value or provide the rejection region.
e. What is your conclusion about the hypothesis test?