A national survey is conducted to assess the association between hypertension and stroke in persons over 55 years of age. Development of stroke was monitored over a 5 year follow-up period. The data are summarized below and the numbers are in millions.
Developed Stroke Did not Develop Stroke
Hypertension 12 37
No Hypertension 4 26
a) What is the sensitivity of the screening test?
b) What is the false positive fraction of the screening test?