Exercise

Swine flu blood test

You go to the doctor about a strong headache. The doctor randomly selects you for a blood test for swine flu, which is suspected to affect 1 in 9,000 people in your city. The accuracy of the test is 99%, meaning that the probability of a false positive is 1%. The probability of a false negative is zero.

Given that you test positive, answer the following questions.

Instructions 1/3

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1
What is the probability that you have swine flu given that your test outcome is positive?

2
You went to Miami and 1 in 350 people came back with swine flu. Calculate the new probability that you'll test positive.
3
If the probability of a false positive is 2%, what is the new probability that you have swine flu after your vacation?