In: Statistics and Probability
Positive Negative
Influenza
A.
360.
7
no influenza A.
6.
1110
find the probability of a subject with a positive test result given that the subject does have influenza A
find the probability of selecting a subject with a negative test result given that the subject does not have influenza a
Positive | Negative | Total | |
Influenza A | 360 | 7 | 367 |
no influenza A | 6 | 1110 | 1116 |
Total | 366 | 1117 | 1483 |
find the probability of a subject with a positive test result given that the subject does have influenza A
P[ positive test | does have influenza A ] = number of positive test and person does not have influenza A / number of does have influenza A
P[ positive test | does have influenza A ] = 6/1116
P[ positive test | does have influenza A ] = 0.005376
find the probability of selecting a subject with a negative test result given that the subject does not have influenza a
P[ negative test | does have influenza A ] = number of negative test and person does not have influenza A / number of does have influenza A
P[ negative test | does have influenza A ] = 1 - P[ positive test | does have influenza A ]
P[ negative test | does have influenza A ] = 1 - 0.005376
P[ negative test | does have influenza A ] = 0.994624