document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1194572>Question 1194572</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Question #9: Working Women and Computer Use<BR>\n" );
document.write( "It is reported that 72% of working women use computers at work. Choose 5 working women at random. Find\r<BR>\n" );
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document.write( "a. The probability that at least 1 doesn’t use a computer at work <BR>\n" );
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document.write( "This is a binomial probability distribution problem.\r<BR>\n" );
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document.write( "n = 5 = sample size<BR>\n" );
document.write( "p = 1-0.72 = 0.28 = probability of a woman not using a computer at work.\r<BR>\n" );
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document.write( "The binomial probability formula we'll use is this<BR>\n" );
document.write( "P(x) = (n C x)*(p)^x*(1-p)^(n-x)<BR>\n" );
document.write( "The n C x refers to the nCr combination formula.<BR>\n" );
document.write( "x = number of women who do not use a computer at work\r<BR>\n" );
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document.write( "Plug in x = 0 to find the probability of exactly 0 women not using a computer at work<BR>\n" );
document.write( "P(x) = (n C x)*(p)^x*(1-p)^(n-x)<BR>\n" );
document.write( "P(0) = (5 C 0)*(0.28)^0*(1-0.28)^(5-0)<BR>\n" );
document.write( "P(0) = (1)*(0.28)^0*(1-0.28)^(5-0)<BR>\n" );
document.write( "P(0) = 0.1934917632\r<BR>\n" );
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document.write( "Then compute the complementary probability.<BR>\n" );
document.write( "P(at least one does not use a computer) = 1 - P(zero women do not use a computer)<BR>\n" );
document.write( "P(at least one does not use a computer) = 1 - P(0)<BR>\n" );
document.write( "P(at least one does not use a computer) = 1 - 0.1934917632<BR>\n" );
document.write( "P(at least one does not use a computer) = 0.8065082368<BR>\n" );
document.write( "This works because we have two options: Either zero women do not use a computer at work, or at least one woman does not use a computer at work.\r<BR>\n" );
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document.write( "The longer method would be to compute it like this<BR>\n" );
document.write( "P(X ≥ 1) = P(1) + P(2) + P(3) + P(4) + P(5)<BR>\n" );
document.write( "I'll let you compute the individual values P(1) through P(5). Follow similar steps mentioned when I computed P(0). \r<BR>\n" );
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document.write( "Answer: 0.8065082368<BR>\n" );
document.write( "Round this value however your teacher instructs.<BR>\n" );
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