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In a random sample of 198 engine crankshaft bearings 33% have a surface finish that is...

In a random sample of 198 engine crankshaft bearings 33% have a surface finish that is rougher than the specifications allow. Find a 90% confidence interval for the proportion of bearins in the population that exceeds the roughness specifications.
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Answer #1

given data are:-

sample size (n) = 198

sample proportion () = 0.33

z critical value for 90% confidence level, both tailed test be:-

the 90% confidence interval for the proportion of bearins in the population that exceeds the roughness specifications is:-

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