1. Suppose that a test for hepatitis has a sensitivity of 95% and a specificity of 90%....

Question:

1. Suppose that a test for hepatitis has a sensitivity of 95% and a specificity of 90%. A person is selected at random from a large population, of which .05% of the people have hepatitis, and given the test. What is the positive predictive value of the test?
2. The probability .0002 (or .02%) in Fig. 7 on page 278 is called the prevalence of the disease. It states that in the population being considered, 2 people per 10,000 have TB. Find the positive predictive value for a population in which 2 people per 100 have TB.
Figure 7