In: Statistics and Probability
(a) The confusion matrix is shown below:
>> Sensitivity = 72.62% = TP / TP + FN
We have TP + FN = 84
Therefore, TP = 72.62% * 84 = 61
FN = 84-61 = 23
>> Specificity = 82.61% = TN / TN + FP
We have TN + FP = 69
Therefore, TN = 82.61% * 69 = 57
FP = 69-57 = 12
Hence we have the confusion matrix as:
(b) Probability of Mr Molina having the disease = TP / TP + FP = 61/ (61 + 12) = 0.835
(c) F- measure = 2TP / 2TP + FP + FN = 2* 61 / (2*61 + 12 + 23) = 0.77
Youden Index = Sensitivity + Specificity - 1
= 72.62 % + 82.61% - 1
= 55.23%
(d) Probability of Mr Ramussen having the disease = TP / TP + FP = 61/ (61 + 12) = 0.8356
Probability of Ms Antonetti not having the disease = TN / TN + FN = 57/ (57 + 23) = 0.7125
(e) Probability for Mr. Bhwana having the disease = 1/4 * 0.8356 = 0.2089
= 1:4 odds