The quality-control manager at a compact fluorescent light bulb (CFL) factory needs to determine whether the mean life of a large shipment of CFLs is equal to 7,548 hours. The population standard deviation is 840 hours. A random sample of 49 light bulbs indicates a sample mean life of 7,368 hours a. At the 0.05 level of significance, is there evidence that the mean life is different from 7,548 hours? b. Compute the p-value and interpret its meaning. c. Construct a 95% confidence interval estimate of the population mean life of the light bulbs. d. Compare the results of (a) and (c). What conclusions do you reach? a. Let u be the population mean. Determine the null hypothesis, Ho, and the alternative hypothesis, H. Ho : H = Hy: HX