document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1122116>Question 1122116</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need your help on the following:\r<BR>\n" );
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document.write( "A.	A child chosen at random in a community school system comes from a low-income family 15 percent of the time. Children from low-income families in the community graduate from college only 20 percent of the time. Children not from low-income families have a 40 percent chance of graduating from college. As an employer of people from this community, you are reviewing applicants and note that the first one had a college degree. What is the probability that the person comes from low-income family?<BR>\n" );
document.write( "B.	By very carefully screening applicants, the Bank of Halifax Country has been able to limit bad-debt losses on consumer loans to 8 percent. What is the probability that at least four of the five loan  applicants that you, as a loan officer trainee, have just approved will repay their loans?<BR>\n" );
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document.write( "Addressing question A again, to confirm the solution by tutor @ikleyn....<br><BR>\n" );
document.write( "This is conditional probability.  We are to find the probability that a child comes from a low income family, GIVEN THAT the child has a college degree.<br><BR>\n" );
document.write( "So the numerator of the probability fraction is all the children from low income families that have a college degree.  15% of the children are from low income families; and 20% of the children from low income families have college degrees.  So the numerator is 20% of 15%: (0.20)(0.15) = 0.03.<br><BR>\n" );
document.write( "The denominator of the probability fraction is ALL the children who have a college degree.  That is 40% of the 85% of children who are not from low income families and 20% of the 15% of the children who are: (0.40)(0.85)+(0.20)(0.15) = 0.34+0.03 = 0.37.<br><BR>\n" );
document.write( "So the probability that the question asks for is 0.03/0.37 = 0.081 or about 8.1%. </SPAN>\n" );
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