A. the author presented the following scenario: suppose that 3% of a population of workers consists of drug users. the drug test has a false positive rate (the probability of a positive drug test given the worker is a non-drug user) of 4% and a false negative rate (the probability of a negative drug test given the worker is a drug user) of 4%. a worker selected from this population is drug tested and found to have a positive result. what is the probability that the worker is a non-drug user? apply bayes' rule to obtain your answer.