document.write( "Question 446013: Hi, I'm stuck with this question, please help me :(
\n" ); document.write( "An economist wishes to estimate the average family income in a certain population. The population standard deviation is known to be $4,500 ; and the economist uses a random sample of size n=225. What is the probability that the sample mean will fall within $800 of the population mean?
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Algebra.Com's Answer #307129 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( "*Note: 
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document.write( "  = 800 , n = 225 and 
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document.write( "    z = 800/4500/15 =  800/300 = 2.6667  P(z < 2.6667 = .9962
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document.write( "And z = -800/300 = -2.6667  P(z < -2.667) = .0038
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document.write( " P( -2.667 > z < 2.6667) = .9962-.0038 = .9924 \n" );
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