SOLUTION: Suppose that HIV test gives a positive result with probability 96% when the patient is indeed affected by HIV, while it gives a negative result with 97% probability when the patien

Algebra ->  Probability-and-statistics -> SOLUTION: Suppose that HIV test gives a positive result with probability 96% when the patient is indeed affected by HIV, while it gives a negative result with 97% probability when the patien      Log On


   



Question 1047567: Suppose that HIV test gives a positive result with probability 96% when the patient is indeed affected by HIV, while it gives a negative result with 97% probability when the patient is not affected by HIV. If a patient is drawn at random from a population in which 12% of individuals are affected by HIV and s/he is found negative, what is the probability that s/he is indeed not affected by HIV?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
======Test+-------Test-=======Total
HIV +===1152=====48========1200
HIV-====264=====8536=======8800
Total====1416=====8584=========10000
If the patient test negative, the probability the person truly is negative is 8536/8584=99.4%