Covid, Bayes' Theorem
"Maths quiz. If you get a positive result on a Covid test that only gives a false positive one time in every 1,000, what’s the chance that you’ve actually got Covid?"
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Covid, Bayes' Theorem
@peter Depends on the incidence rate of COVID-19. If there are 1,000 people, and one has COVID-19, and one is a false positive, and you got a positive result then it is 50/50 if you are the real one or the false.
If the incidence rate was 3 per 1,000, then 75% chance you have it; if incidence rate was 0.11 per 1,000 then only 10% chance a positive result is real.
