document.write( "Question 1050519: You are estimating the cost of engine overhauls. A sample of 99 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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\n" ); document.write( " 268.20 ≤ μ ≤ 301.80
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\n" ); document.write( " 273.18 ≤ μ ≤ 296.82
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\n" ); document.write( " 271.00 ≤ μ ≤ 299.00
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\n" ); document.write( " 281.61 ≤ μ ≤ 288.39
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Algebra.Com's Answer #666082 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi  
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document.write( " CI	z = value
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document.write( "90%	z =1.645
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document.write( "92%	z = 1.751
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document.write( "95%	z = 1.96
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document.write( "98%	z = 2.326
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document.write( "99%	z = 2.576
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document.write( "95% Confidence Interval:  z = 1.96,  n = 99, m = 285
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document.write( "ME =
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document.write( "ME = 1.96*60/sqrt(99) = 11.82
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document.write( "285 - ME <  < 285+ ME
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document.write( "285 - 11.82 <  < 285+ 11.82
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document.write( "273.18 ≤ μ ≤ 296.82 
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