document.write( "Question 390115: what is the probability that exactly 5 out of 15 test subjects fail a test in a 94% success rate? \n" ); document.write( "
Algebra.Com's Answer #276581 by Edwin McCravy(20054)\"\" \"About 
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what is the probability that exactly 5 out of 15 test subjects fail a test
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document.write( "Since the problem is about failures, and binomial probability is about\r\n" );
document.write( "successes, we have two choices. Either consider a failure to be a success,\r\n" );
document.write( "which sounds contradictory, or to rewrite the problem in terms of successes.\r\n" );
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document.write( "I will choose to rewrite the problem in terms of successes, using the fact\r\n" );
document.write( "that saying \"exactly 5 out of 15 fail\" is the same as saying \"exactly 10 out of\r\n" );
document.write( "15 succeed\". So we rewrite the problem as:\r\n" );
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\n" ); document.write( "what is the probability that exactly 10 out of 15 test subjects succeed in
\n" ); document.write( "passing a test in a 94% success rate?
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document.write( "The probability of getting exactly x successes out of n trials where the\r\n" );
document.write( "probability of 1 success in 1 trial is p, is given by the formula\r\n" );
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document.write( "C(n,x)pxqn-x where q = 1 - p\r\n" );
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document.write( "Here n = 15, x = 10, p = .94, q = 1-.94 = .06\r\n" );
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document.write( "C(15,10)(.94)10(.06)15-10\r\n" );
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document.write( "3003(.94)10(.06)5 = .0012577378\r\n" );
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document.write( "Edwin
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