Question

When testing for a disease such as the flu, there is always the possibility of receiving a false negative (meaning that you have the disease but tested negative) and a false positive (meaning that you do not have the disease but tested positive).

Last month, a collection of people at a clinic were tested for the flu. After the results were confirmed after medication, here were the results.

	Tested Positive	Tested Negative
Had Disease	816	26
Didn’t Have Disease	31	917

1. 1) How many people were used in this study?

2. 2) What is the probability that someone at this clinic tested positive for the flu and actually had the flu?

3. 3) What is the probability that someone at this clinic tested negative for the flu and actually did not have the flu?

4. 4) What is the probability that someone tested at this clinic got a test result that was correct?

5. 5) What is the probability that someone tested at this clinic got an incorrect test result?

6. 6) What is the probability that a false positive was obtained? (Hint: This is the probability that someone tested positive, given that they actually did not have the flu).

7. 7) What is the probability that a false negative was obtained? (Hint: This is the probability that someone tested negative, given that they actually did have the flu).

8. 8) Looking at the rates in #5, 6, and 7, do you feel that this clinic’s error rate is too high? Support your answer with your thinking on this. (An answer of ‘yes’ or ‘no’ only will notreceive credit).

Answer 1