document.write( "Question 857153: the population standard deviation fro a gas mileage for a certain model of car is known to be 1.8 miles per gallon. how many cars would you have to test(what sample would you need)to get a margin of error of 0.5 mile per gallon (or less) for the population mean at a 90%confidence level? \n" ); document.write( "

Algebra.Com's Answer #516387 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!

 
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document.write( "Hi,
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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( "ME = .5 =
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document.write( "  sqrt(n) = 1.645*1.8/.5 = 5.922   
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document.write( "       n= 35.07 0r  approximately 36 
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