Answer Happy

After almost two years of the pandemic. Martina and Robin organise a large party, Each of them invites 50 friends. Martina and Robin want to avoid a super-spreader event, so they send antigen tests along with the invitations. The test they got has a 7% false-positive rate and a 2% false negative rate. Their idea is straightforward: . If the number of positive tests is higher than what they can expect by chance if no one has covid, they will ask everyone to take a PCR test and only those with a negative PCR will get to come to the party . If the number of positive tests is below what they would by chance if no one has covid, they will not require PCR tests and everyone can come to the party a. If none of the invitees has Covid, how many positive tests should they expect? (Round your answer to the largest integer) At this stage of the pandemic, 1.5% of the population has Covid-19 in any given two weeks: b). What is the probability that someone that tested positive in the antigen test has Covid? (Round your answer to 2 decimal places) c. How would you justify your answer?

PADPH) PHP) PAPI) PAWPB) PYCAM PY) PAD) A Let A denote being sick and B denote testing positive. Then Pr(BIA) where Pr(AB) = 0.02 is the rate of correct positives, Pr(AB) = 0.07 is the rate of false positives, Pr(B) = 0.015 is the probability of having Covid and Pr(BC) = 1 -0.015 is the probability of not having Covid. B. Let A denote being sick and B denote testing positive. Then Pr(BA) where Pr(AB)=10.05 is the rate of correct positives, Pr(AB) = 0.07 is the rate of false positives. Pr(B) 0.015 is the probability of having Covid and Pr(B) = 1 -0.015 is the probability of not having Covid. C Let B denote being sick and A denote testing positive. Then Pr(BLA) where Pr(AB) - 0.02 is the rate of correct positives, Pr(AB) - 0.07 is the rate of false positives. Pr(B) 0.015 is the probability of having Covid and Pr(B) = 1 -0.015 is the probability of not having Covid. PM D. Let B denote being sick and A denote testing positive. Then Pr(BLA) where PHAB) = 1 -0.05 PAD) PDI) PRIBOP(0) is the rate of correct positives. Pr(AB) = 0.07 is the rate of false positives, Pr(B) = 0.015 is the probability of having Covid and Pr(B) = 1 -0.015 is the probability of not having Covid. E. None of the above. (Please justify your answer in the comment box) PB) PAM8) Mar