document.write( "Question 1075774: Three hundred people apply for three jobs. Sixty of the applicants are women.
\n" ); document.write( "(a) If three people are selected at random, what is the probability that all are women? (Round your answer to six decimal places.)
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Algebra.Com's Answer #690471 by Theo(13342)\"\" \"About 
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the probability that the first applicant will be a woman is 60/300.\r
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\n" ); document.write( "\n" ); document.write( "assuming the first is a woman, then the probability that the second will be a woman is 59/299.\r
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\n" ); document.write( "\n" ); document.write( "assuming the second is a woman, then the probability that the third will be a woman is 58/298.\r
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\n" ); document.write( "\n" ); document.write( "the probability that they will all be women is therefore 60/300 * 59/299 * 58/298.\r
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\n" ); document.write( "\n" ); document.write( "this becomes equal to .0076810846\r
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\n" ); document.write( "\n" ); document.write( "alternately this can be viewed as the number of ways you can get 3 women out of 60 divided by the number of ways you can get 3 people out of 300.\r
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\n" ); document.write( "\n" ); document.write( "that would be c(60,3) / c(300,3) = .0076810846.\r
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\n" ); document.write( "\n" ); document.write( "c(60,3) = 60! / (3! * 57!)\r
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\n" ); document.write( "\n" ); document.write( "c(300,3) = 300! / (3! * 297!)\r
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\n" ); document.write( "\n" ); document.write( "in general, c(n,x) = n! / (x! * (n-x)!)\r
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\n" ); document.write( "\n" ); document.write( "the calculator i used is the ti-84 plus.\r
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\n" ); document.write( "\n" ); document.write( "it can do c(300,3) but it can't do 300! / (3! * 297!).\r
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\n" ); document.write( "\n" ); document.write( "for whatever the reasons, the combination formula works but the equivalent factorial formula doesn't work.\r
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\n" ); document.write( "\n" ); document.write( "it has to do with internal storage requirements in the calculator.\r
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\n" ); document.write( "\n" ); document.write( "300! is just too large for it to handle.\r
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\n" ); document.write( "\n" ); document.write( "i used excel as well but that can't handle it either.\r
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\n" ); document.write( "\n" ); document.write( "surprisingly, both excel and the ti-84 could handle c(300,3).\r
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\n" ); document.write( "\n" ); document.write( "bottom line is the results are accurate but if you try to duplicate c(300,3) by using the equivalent formula of 300! / (3! * 297!) you will have difficulty.\r
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