Swedish researchers investigated the relationship between chocolate consumption and stroke. the researchers gave a questionnaire about eating habits to a randomly selected sample of swedish men. based on the responses to the questionnaire, the men were classified into two groups. group a consisted of the 9,250 men who ate the most chocolate per week, and group b consisted of the 9,250 men who ate the least chocolate per week. the researchers tracked the men's health for ten years. during that time, there were 458 cases of stroke among the men in group a and 543 cases of stroke among the men in group
b.