document.write( "Question 464956: In a certain high-risk group, the chance of a person having suffered a heart attack is 70%. If four persons are chosen from the group, find the probability that at least one will have had a heart attack. \n" ); document.write( "

Algebra.Com's Answer #318511 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi,
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document.write( "Note: The probability of x successes in n trials is: 
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document.write( "P = nCx*  where p and q are the probabilities of success and failure respectively. 
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document.write( "In this case p= .70 and q = .30
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document.write( "nCx = 
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document.write( "P(at least one in four) = 1 - P(none)
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document.write( "                              P(none) = .30^4
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document.write( "P(at least one in four) = 1 - .30^4 = .9919 \n" );
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