Question

A test for the presence of a certain disease has probability 0.2 of giving a false-positive result (indicating that an individual has the disease when this is not the case) and probability 0.1 of giving a false-negative result. Suppose that 10 individuals are tested, 5 of whom have the disease and 5 whom do not. Let X be the number of positive readings that result.
a. Explain why X does not have a binomial distribution.

b. Find the probability that exactly 3 of the 10 test results is positive?

Answer 1

For the part b of the question please find the attached image.