Final answer:
The proportion of men who developed coronary heart disease is approximately 0.1313 or 13.13%.
Step-by-step explanation:
The proportion of men who developed coronary heart disease can be calculated by dividing the number of men who developed CHD by the total number of men observed. In this case, the proportion would be:
Proportion = Number of men who developed CHD / Total number of men observed
Substituting the given values into the equation:
Proportion = 81 / 617 ≈ 0.1313
Therefore, the proportion of men who developed coronary heart disease is approximately 0.1313 or 13.13%.