At a large factory 1% of the workers are using drugs, an eventwe’ll call D. An employee has just been tested by a procedure thathas a 3% false positive rate and has failed the test, F. Assumethat the test is always positive for people who are using drugs.(i) Find P(D|F). (ii) Suppose that the employee failed the firsttest (F1). What is the probability he will fail the second test(F2), i.e., compute P(F2|F1). (iii) What is the probability he isusing drugs if he fails both tests, i.e., P (D|F1 ∩ F2).
