Question 599706: Perform a hypothesis test for the following problem. Use the same format as the hypothesis test worksheets.
An office building complex uses thousands of fluorescent light bulbs each year. The brand of bulb it currently uses has a mean life of 900 hours. A manufacturer claims that its new brand of bulbs, which cost the same as the brand the complex currently uses, has a mean life of more than 900 hours. The office building’s management has decided to purchase the new brand if, when tested, the evidence supports the manufacture’s claim at the 0.05 significance level. Suppose 64 bulbs were tested with the following results: x̅ = 920 hours, s = 80 hours. Will the office building management purchase the new brand of fluorescent bulbs?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! An office building complex uses thousands of fluorescent light bulbs each year. The brand of bulb it currently uses has a mean life of 900 hours. A manufacturer claims that its new brand of bulbs, which cost the same as the brand the complex currently uses, has a mean life of more than 900 hours. The office building’s management has decided to purchase the new brand if, when tested, the evidence supports the manufacture’s claim at the 0.05 significance level. Suppose 64 bulbs were tested with the following results: x̅ = 920 hours, s = 80 hours. Will the office building management purchase the new brand of fluorescent bulbs?
-----------------
Ho: u <= 900
Ha: u > 900 (claim)
-----
x-bar = 920
---
z(920) = (920-900)/[80/sqrt(64)] = 20/[10) = 2
---
p-value = P(z > 2) = normalcdf(2,100) = 0.0228
----
Since the p-value is less than 5%, reject Ho.
The test results support the claim.
===============
Cheers,
Stan H.
|
|
|
