Question

Problem Nine A test for a certain disease was given to 1,000 subjects, 8% of whom were known to have the disease. For the subjects who had the disease, the test had a positive result for the disease in 90% of the subjects, was inconclusive for 7% and a negative result in 3% of the subjects. For subjects who did not have the disease, the test had a positive result in 5% of subjects, was inconclusive in 10% and a negative result in the remaining 85%.

A. Draw a tree diagram to model the probabilities in this problem.
  
B. What is the probability of a randomly selected person having the disease GIVEN that the test has a positive result?

C. Which theorem/rule did you apply to solve this problem?

Answer 1

(a) disease Not disease 0.92 0.08 Negative inconeludise Positive Positive Negative 10.03 0.85 0,90 یہ,4 0.10 0.07 0.072 0.0056 0.0024 0.782 0.046 0.092 (6) pl berson has disease given (0.08) (0.9) test has positive refurt :) (0.08) (0.90) + (0.92) (0.05) 0.07 W 0.118 = 0.6101694915 50. 6102 (0) Bayel' Theorem.