Question

1) The table below classifies 555 subjects by drug use and drug test result. Subject Uses Drugs Positive Test Result (Test shows drug use.) 45 (True Positive) 25 (False Positive) Negative Test Result (Test shows no drug use.) 5 (False Negative 480 (True Negative) Subject Does Not Use Drugs a) If a subject is selected at random, find the probability this person uses drugs given that the test result is negative. (a) Express this statement in probability notation. (b) Find the probability. b) If two subjects are randomly selected without replacement, find the probability the first selected person does not use drugs and the second selected person does not use drugs. You must use probability notation to express the solution to this problem.

Answer 1

In this Negative Test rescills positive Test Results 45 50 5 Subject was drugs 25 480 505 Subject does not uses drug 555 485 70 a) Plusedrug and negative) Penegative) 51555 b.) The probability a 10.0103 4851555 b) If two subjects are randomly selected without Yeplacement pl first person does not use dreg and second person does not use drug Pl ist person does not ugedrig (does not wedrug) 505 50€ = 6.8278 555 554 and person JAP/ *