The fan blades on commercial jet engines must be replaced when wear on these parts indicates too much variability to pass inspection. If a single fan blade broke during operation, it could severely endanger a flight. A large engine contains thousands of fan blades, and safety regulations require that variability measurements on the population of all blades not exceed ?2 = 0.18 mm2. An engine inspector took a random sample of 61 fan blades from an engine. She measured each blade and found a sample variance of 0.29 mm2. Using a 0.01 level of significance, is the inspector justified in claiming that all the engine fan blades must be replaced? (c) Find or estimate the P-value of the sample test statistic. (f) Find a 90% confidence interval for
The fan blades on commercial jet engines must be replaced when wear on these parts indicates too much variability to pass inspection. If a single fan blade broke during operation, it could severely endanger a flight. A large engine contains thousands of fan blades, and safety regulations require that variability measurements on the population of all blades not exceed ?2 = 0.18 mm2. An engine inspector took a random sample of 61 fan blades from an engine. She measured each blade and found a sample variance of 0.29 mm2. Using a 0.01 level of significance, is the inspector justified in claiming that all the engine fan blades must be replaced?
(c) Find or estimate the P-value of the sample test statistic.
(f) Find a 90% confidence interval for the population standard deviation
Given that
Sample size (n)=61
Sample variance (s2)=0.29
Level of significance =0.01
Population variance =0.18
We will test the hypothesis for the claim that blades are not exceed 0.18
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