SOLUTION: You are estimating the cost of engine overhauls. A sample of 49 repairs showed an average overhaul of 285 hours with a standard deviation of 60 hours. Calculate a 95% confidence in

Question 995165: You are estimating the cost of engine overhauls. A sample of 49 repairs showed an average overhaul of 285 hours with a standard deviation of 60 hours. Calculate a 95% confidence interval for the average overhaul. (Carry intermediate calculations to three decimal places.)

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
You are estimating the cost of engine overhauls. A sample of 49 repairs showed an average overhaul of 285 hours with a standard deviation of 60 hours. Calculate a 95% confidence interval for the average overhaul. (Carry intermediate calculations to three decimal places.)
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Sample mean:: 285
ME = 1.96(60/sqrt(49) = 1.96(60/7) = 16.8
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95% CI:: 285-16.8 < u < 285+16.8
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Cheers,
Stan H.
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