Brain Teasers & Mental Math
A test for a disease is 99% accurate (99% sensitivity and 99% specificity). The disease affects 1 in 10,000 people. You test positive. What is the probability you actually have it?
Model answer
Bayes. Per 1,000,000 people: ~100 have it, 99 test positive (true positives). Of 999,900 healthy, 1% = 9,999 test positive (false…
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