Assume that a narcotics test gives positive results in 99% for drug users. For people not using narcotics the test gives negative results in 98% of cases. A company decided to test its employees knowing that 0.5% of them use drugs. Estimate the probability that a person with a positive test result is indeed a user. Estimate using the NETICA software. Hi, I'm studying Civil Engineering and now I have some humanity courses. For subject Decision Making and Negotiation Theory I have to do above problem. Can anyone know Netica and can help me? Thx.