3. A prospective cohort study is run to estimate the incidence of stroke in persons 55 years of age and older. All participants are free of stroke at study start.

Each participant is followed for a maximum of 5 years. The data are summarized below. a. What is the annual incidence rate of stroke in men? b. What is the annual incidence rate of stroke in women? c. What is the annual incidence rate of stroke (men and women combined)? \begin{array}{|l|c|c|} & \text{^^20Number^^20of^^20Strokes^^20} & \begin{array}{c}\text{^^20Number^^20of^^20Stroke^^20Free^^20} \\ \text{^^20Person^^2dYears^^20}\end{array} \\ \text{^^20Men^^20}(\mathrm{n}=125) & 11 & 487 \\ \text{^^20Women^^20}(\mathrm{n}=200) & 24 & 947 \\ \end{array}