Question

Suppose a drug test is 91% sensitive and 83% specific. That is, the test will produce 91% true positive results for drug user

0 0
Add a comment Improve this question Transcribed image text
Answer #1

Consider: A1 = Person is a drug user

A2 = Person is not a drug user

B = Event = Positive drug test result

Required output is: P(A1|B)

Prior probabilities P(A1) = 0.023 and P(A2) = 1-0.023 = 0.977

P(B|A1) = 0.91

P(B|A2) = 0.09

Posterior probability:

P(A1|B) = [P(B|A1)*P(A1) ] / [P(B|A1)*P(A1) + P(B|A2)*P(A2) ]

= (0.91*0.023)/(0.91*0.023 + 0.09*0.977)

=0.192265295

=19.23%

Thus, the correct answer is 19.23%

Add a comment
Know the answer?
Add Answer to:
Suppose a drug test is 91% sensitive and 83% specific. That is, the test will produce...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • 18. Drug Screening If one of the test subjects is randomly seleci the subject had a...

    18. Drug Screening If one of the test subjects is randomly seleci the subject had a positive test result or does not use drugs. 19. Drug Screening if one of the subjects is randomly selected, find the probability that the subject had a negative test result or does not use drugs. Whiarre is randomly selected, find the probability that the Negative Test (Drug Use Is Not Indicat Table 4-1 Pre-Employment Drug Screening Results Positive Test Result (Drug Use Is Indicated)...

  • Medical screening tests are used to check for the presence on disease, evidence of illegal drug...

    Medical screening tests are used to check for the presence on disease, evidence of illegal drug use, etc. The its sensitivity and its specificity. The sensitivity among those with the condition that will test positive. The specichy proportion among those without the condition that will test neg sensitivity of a test is defined to be the conditional ng those without the condition that will test negative. More formally, the test is defined to be the conditional probability that a person...

  • A supreme court from a certain region recently ruled that employees can be tested for drugs...

    A supreme court from a certain region recently ruled that employees can be tested for drugs only if management has reasonable cause to administer the test. An article in a certain magazine focused on the misclassification rates of such drug tests. A false positive occurs when a drug test administered to a non-drug user yields a positive result. A false negative cours when a drug test administered to a drug user yields a negative result Complete parts a and b....

  • Suppose that a drug test has a 0.94 probability of successfully identifying a drug user, but...

    Suppose that a drug test has a 0.94 probability of successfully identifying a drug user, but has a 0.09 probability of reporting a false positive. A company drug tests it's employees and 12% of them test positive for drug use. Let T denote "tests positive for drug use" and D denote "drug user." The probability 0.94 above refers to? The probability 0.09 above refers to? The percentage 12% above refers to? What is the probability a random employee of this...

  • A supreme court from a certain region recently ruled that employees can be tested for drugs...

    A supreme court from a certain region recently ruled that employees can be tested for drugs only if management has reasonable cause to administer the test. An article in a certain magazine focused on the misclassification rates of such drug tests. A false positive occurs when a drug test administered to a non-drug user yields a positive result. A false negative occurs when a drug test administered to a drug user yields a negative result. Complete parts a and b...

  • The data represent the results for a test for a certain disease. Assume one individual from...

    The data represent the results for a test for a certain disease. Assume one individual from the group is randomly selected. Find the probability of getting someone who tests negative, given that he or she had the disease The individual actually had the disease Yes No Positive Negative The probability is approximately (Round to three decimal places as needed)

  • Refer to the sample data for pre-employment drug screening shown below. If one of the subjects...

    Refer to the sample data for pre-employment drug screening shown below. If one of the subjects is randomly selected, what is the probability that the test result is a false positive? Who would suffer from a false positive result? Why? Positive test result Drug Use Is Indicated Negative test result Drug Use Is Not Indicated Subject Uses Drugs Subject Is Not a Drug User Pre-Employment Drug Screening Results The probability of a false positive test result is (Round to three...

  • The data represent the results for a test for a certain disease. Assume one individual from...

    The data represent the results for a test for a certain disease. Assume one individual from the group is randomly selected. Find the probability of getting someone who tests negative, given that he or she had the disease. Yes No Positive 131   13 Negative . 35 121 The probability is approximately ________. ​(Round to three decimal places as​ needed.)

  • 12. Suppose 500 athletes are tested for a drug, one in twenty has used the drug,...

    12. Suppose 500 athletes are tested for a drug, one in twenty has used the drug, the test has a 98% specificity and the test has a 100% sensitivity. That is, the probability of a false positive is 2% and there is no chance that the user of the drug will go undetected. Construct a tree diagram showing the probabilities associated with this problem. Write a probability on each branch (6 branches). Multiply the the probabilities along each path and...

  • 12. Suppose 500 athletes are tested for a drug, one in twenty has used the drug,...

    12. Suppose 500 athletes are tested for a drug, one in twenty has used the drug, the test has a 98% specificity and the test has a 100% sensitivity. That is, the probability of a false positive is 2% and there is no chance that the user of the drug will go undetected. Construct a tree diagram showing the probabilities associated with this problem. Write a probability on each branch (6 branches). Multiply the the probabilities along each path and...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT