Disease Test. Suppose a test for a disease is 90% accurate for those who have the disease...

Disease Test. Suppose a test for a disease is 90% accurate for those who have the disease (true positives) and 90% accuiate for those who do not have the disease (true negatives). Within a sample of 4000 patients, the incidence rate of the disease is the national average, which is 1.5%.

a. Verify that the entries in the table below follow from the information given and that the overall incidence rate is 1.5%. Explain.

	Disease	No Disease	Total
Test Positive	54	394	448
Test Negative	6	3546	3552
Total	60	3940	4000

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b. Of those with the disease, what percentage test positive?

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c. Of those who test positive, what percentage have the disease? Compare this result to the one in part b and explain why they are different.

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d. Suppose a patient tests positive for the disease. As a doctor using this table, how would you describe the patient’s chance of actually having the disease? Compare this figure to the overall incidence rate of the disease.