Section B: Decision Making Techniques (Total Marks: 33 marks) Question 3 (6 marks) Suppose that 10% of people in the population are users of the drug. Prob (+Test Result|Drug User) = 0.995 Prob (-Test Result|Drug User) = 0.005 Prob (+Test Result|Non Drug User) = 0.05 Prob (-Test Result|Non Drug User) = 0.95 Prob (ANB) Note: Prob (AJB) = Prob (B) Required: What is the probability that a randomly selected individual with a positive test is a drug user? (b) What is the probability that a randomly selected individual with a negative test is a non-drug user? Solutions