<prompt> A population of 1000 people in whom the prevalence of disease XYZ is 50. ABC screening test was used to screen disease which has specificity and sensitivity of 50 . What is positive predictive value of screening test ABC.50257510  <response>: Total Population 1000 Prevalence 50 People have Disease 500 Not have Disease 500 Method 1 Test Disease ? Th ? A TP ? B FP ? Th C FN ? D TN ? 500 given 500 given 1000 given Test Disease ? Th ? A 250 B 250 Th C 250 D 250 Method 2 Bayes Theorum 