document.write( "Question 1161376: The mean and standard deviation of the binomial distribution are 4 and 1.633 respectively. Find n,p and the distribution function at X=3.
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Algebra.Com's Answer #784937 by Edwin McCravy(20065)\"\" \"About 
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The mean and standard deviation of the binomial distribution are 4 and 1.633
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document.write( "\"system%28mu=4=np%2Csigma=1.633=sqrt%28np%281-p%29%29%29\"\r\n" );
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document.write( "Substitute 4 for np in the second equation\r\n" );
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document.write( "\"1.633=sqrt%28%281-p%29%29\" \r\n" );
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document.write( "Square both sides\r\n" );
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document.write( "\"1.633%5E2=%28sqrt%284%281-p%29%29%29%5E2\"\r\n" );
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document.write( "\"2.666689=4%281-p%29\"\r\n" );
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document.write( "Distribute:\r\n" );
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document.write( "\"2.666689=4-4p\"\r\n" );
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document.write( "Add -4 to both sides\r\n" );
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document.write( "\"-1.333311=-4p\"\r\n" );
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document.write( "Divide both sides by -4\r\n" );
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document.write( "\"0.33332775=p\"\r\n" );
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document.write( "Substitute in\r\n" );
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document.write( "\"4=np\"\r\n" );
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document.write( "\"4=n%280.33332775%29\"\r\n" );
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document.write( "Divide both sides by 0.33332775\r\n" );
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document.write( "\"12.000201=n\"\r\n" );
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document.write( "I'd round off to p = 0.3333 and n = 12\r\n" );
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document.write( "On your TI-84\r\n" );
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document.write( "press 2nd vars and scroll to A:binompdf(\r\n" );
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document.write( "make it read this\r\n" );
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document.write( "trials:12\r\n" );
document.write( "p:3333\r\n" );
document.write( "x value:3\r\n" );
document.write( "Paste\r\n" );
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document.write( "Scroll down to \"Paste\"\r\n" );
document.write( "Press enter\r\n" );
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document.write( "read\r\n" );
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document.write( "binompdf(12,0.3333,3)\r\n" );
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document.write( "Press enter\r\n" );
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document.write( "0.2119838219    <--answer\r\n" );
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document.write( "Edwin
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