document.write( "Question 32804: A box contains 35 machine parts, 8 of which are defective. A quality control inspector randomly selects 5 of the 35 parts for testing. What is the probablility that at least one part is defective? \n" ); document.write( "
Algebra.Com's Answer #19244 by longjonsilver(2297)\"\" \"About 
You can put this solution on YOUR website!
just think about all the different permutations here: the question is asking for the probability of there being 1 or 2 or 3 or 4 or 5 defectives in his sample: call this P(A). This is very complicated to do. Well, not complicated as susch, just time consuming and boring as Hell after about 3 minutes!\r
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\n" ); document.write( "\n" ); document.write( "However, we can use the fact that P(A) = 1 - P(not A) to make our work simpler.\r
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\n" ); document.write( "\n" ); document.write( "If we can find the probability that the inspector picks 5 pieces that are not defective and then take this away from 1, we will have our answer.\r
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\n" ); document.write( "\n" ); document.write( "So, P(all 5 are not defective) = (27/35)*(26/34)*(25/33)*(24/32)*(23/31)
\n" ); document.write( "P(all 5 are not defective) = 0.24868\r
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\n" ); document.write( "\n" ); document.write( "So, P(at least one defective) = 1 - 0.24868
\n" ); document.write( "P(at least one defective) = 0.75132\r
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\n" ); document.write( "\n" ); document.write( "jon.
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