Question

26. 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 7510 hours. The population standard deviation is 910 hours. A random sample of 49 light bulbs indicates a sample mean life of 7,302 hours.

At the 0.05 level of​ significance, is there evidence that the mean life is different from 7510 hours?

Determine the null​ hypothesis, and the alternative​ hypothesis,

What is the test​ statistic?

What​ is/are the critical​ value(s)?

What is the final​ conclusion?

What is the​ p-value?

Interpret the meaning of the​ p-value.

Construct a​ 95% confidence interval estimate of the population mean life of the light bulbs.

Compare the results of​ (a) and​ (c). What conclusions do you​ reach?

Compare the results of parts​ (a) through​ (d) to those when the standard deviation is 700 hours.

Answer 1