document.write( "Question 1061648: Tutors A certain disease has an incidence rate of 0.5%. If the false negative rate is 7% and the false positive rate is 2%, compute the probability that a person who tests positive actually has the disease. \n" ); document.write( "

Algebra.Com's Answer #698664 by jorel1380(3719) $\"\"$ $\"About$

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Consider a population of 100,000 who get the test. Of those people, .5%, or 500 people actually have the disease, but 7% will test negative, so 465 out of those 500 will test positive. Of the 99,500 who don't have the disease, 2%, or 1990 will test positive. In total, 2,455 will test positive, of which 465 will actually have the disease. So the ratio of diseased to positive tests is 465/2455 , or 0.18941. This is the probability that someone who tested positive actually has the disease. ☺☺☺☺ \n" ); document.write( "

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