The quality-control manager at a compact fluorescent light bulb(CFL) factory needs to determine whether the mean life of a largeshipment of CFLs is equal to 7.505 hours. The population standarddeviation is 100 hours. A random sample of 64 light bulbs indicatesa sample mean life of 7.480 hours.
a. At the 0.05 level of significance, is thereevidence that the mean life is different from 7.505 hours?
b. Compute the p-value and interpret itsmeaning.
c. Construct a 95% confidence interval estimateof the population mean life of the light bulbs.
d. Compare the results of (a) and (c). Whatconclusions do you reach?
