SOLUTION: The probability of a randomly selected adult in one country being infected with a certain virus is 0.005. In tests for the virus, blood samples from 24 people are combined. What
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Question 1152816: The probability of a randomly selected adult in one country being infected with a certain virus is 0.005. In tests for the virus, blood samples from 24 people are combined. What is the probability that the combined sample tests positive for the virus? Is it unlikely for such a combined sample to test positive? Note that the combined sample tests positive if at least one person has the virus. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! This is 0.995 probability that an adult will not test positive.
For combining 24 people, assuming independence, the probability of not testing positive is now 0.995^24=0.8867
so the answer to the first is the complement or 0.1133
That would not be considered unlikely, although the word's definition would need to be clarified. With a rare disease (1/2000) to have a 1/10 probability of being positive represents a considerable degrading of the test.
