A genetic condition is found that affects 10% of adults in the U.S. population. In a city with 100,000, that means that approximately 10,000 people have the condition, and 90,000 people do not. Fortunately, there is a genetic test for the gene that causes the disease. The test has an error rate of 1% (that is, 1% of people tested get the wrong result). This means that if we test all 100,000 people.
- Of the 10,000 people who have the condition, 1% of them will have false negatives. In other words, this test will not detect the condition in 1% of the people who actually do have the condition.
- If false positives also occur at the rate of 1%, then about 1% of the 90,000 people who do not have the bad gene will test positive.
What an individual really wants to know, and the questions you need to answer, are:
- In this city, how many people receive a positive test result? How many people who test positive actually do not have the condition? What percent of people who get a positive test result don’t have the condition? This is the false-positive rate.
- In this city, how many people receive a negative test result? How many people who test negative actually have the condition? What percent of people who get a negative test result have the condition? This is the false-negative rate.
|Due By (Pacific Time)
||12/08/2013 10:00 pm