<PRE><B>Question 616221</B>
A government survey conducted to estimate the mean price of houses in a metropolitan area is designed to have a margin of error of $10,000. Pilot studies suggest that the population standard deviation is $70,000. Estimate the minimum sample size needed to estimate the population mean with the stated accuracy. 
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ME = z*s/sqrt(n)
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n = [z*s/ME]^2
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n = [1.96*70000/10000]^2 = [1.96*7]^2 = 189 when rounded up
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Note: I assumed you wanted 95 degree confidence.
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Cheers,
Stan H.</PRE>