document.write( "Question 1175196: Mensa is an organization whose members possess IQ that are in the top 2% of the population. It is given that IQs are normally distributed with a mean of 100 and a standard deviation of 15.
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\n" ); document.write( "\n" ); document.write( "(b) Find the minimum IQ needed to be a Mensa member. (4 marks)
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Algebra.Com's Answer #800772 by ewatrrr(24785)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Hi\r\n" );
document.write( "Normal Distribution:   μ = 100   σ = 15\r\n" );
document.write( "Using TI Calculator or similarly one like a Casio fx-115 ES plus:\r\n" );
document.write( "P( 85 < x < 109) = normalcdf(85,109,15,100) =.5671  0r 56.71%\r\n" );
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document.write( "'Highly recommend' using a Calculator when working with Normal Distributions.\r\n" );
document.write( "w/o recommend checking one's calculations with online sources such as stattrek.com \r\n" );
document.write( "0r keisan.casio.com has great illustrations, as Shown below.\r\n" );
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document.write( "Note: | \"z+=blue+%28x+-+mu%29%2Fblue%28sigma%29\" and curve continuous\r\n" );
document.write( "P(85< x <109) = P(x ≤ 109) - P(x ≤ 85) = P(z ≤ 9/15) - P(z ≤ -15/15) \r\n" );
document.write( "  .\r\n" );
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document.write( "b) top 2% (1-.02 = .98) z = 2.0537   &  x = z*σ +  μ \r\n" );
document.write( " x = 2.0537*15 + 100 = 130.806\r\n" );
document.write( "Or \r\n" );
document.write( "Using TI Calculator or similarly one like a Casio fx-115 ES plus:\r\n" );
document.write( "P(top 2%) = invNorm(.98,15,100) = 130.806\r\n" );
document.write( "  131  the minimum IQ needed to be a Mensa member. \r\n" );
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document.write( "Wish You the Best in your Studies.\r\n" );
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