<prompt> Numerator in calculating positive predictive value -True positiveFalse positiveTrue negativeFalse negative  <response>: Ans. is a i.e., True positive Sensitivity Number of true positive---Number of true positives Number of false negative Specificity Number of true negatives---Number of true negative number of false positives. Positive predictive value -True positive---True positive False positive Negative predictive value True negative---True negative False negative 