Thequality-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 7,547 hours. The population standard deviation is 92hours. A random sample of 64 light bulbs indicates a sample mean life of 7,524 hours.

a. At the 0.05 level ofsignificance, is there evidence that the mean life is different from 7,547hours?

b. Compute thep-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 youreach?

a. Let be the population mean. Determine the nullhypothesis, H0, and the alternativehypothesis, H1.

H0: =_____

H1:______

What is the teststatistic?

ZSTAT=

Whatis/are the criticalvalue(s)?_______

What is the finalconclusion?

A.Fail to reject H0. There is not isnot sufficient evidence to prove that the mean life is different from 7,547 hours.

B.Reject H0. There is sufficient evidence to prove that the mean life is different from 7,547 hours.

C.Reject H0. There isnot sufficient evidence to prove that the mean life is different from 7,547 hours.

D.Fail to reject H0. There is sufficient evidence to prove that the mean life is different from 7,547 hours.

b. What is thep-value?____

Interpret the meaning of thep-value. Choose the correct answer below.

A.Fail to reject H0. There isnot sufficient evidence to prove that the mean life is different from 7,547 hours.

B.Reject H0. There isnot sufficient evidence to prove that the mean life is different from 7,547 hours.

C.Fail to reject H0. There is sufficient evidence to prove that the mean life is different from 7,547 hours.

D.Reject H0. There is sufficient evidence to prove that the mean life is different from 7,547 hours.

c. Construct a95% confidence interval estimate of the population mean life of the light bulbs.

____u_____

d. Compare the results of(a) and(c). What conclusions do youreach?

A.The results of(a) and(c) are not thesame: there isnot sufficient evidence to prove that the mean life is different from 7,547 hours.

B.The results of(a) and(c) are thesame: there is sufficient evidence to prove that the mean life is different from 7,547 hours.

C.The results of(a) and(c) are not thesame: there is sufficient evidence to prove that the mean life is different from 7,547 hours.

D.The results of(a) and(c) are thesame: there isnot sufficient evidence to prove that the mean life is different from 7,547 hours.