16. Suppose that a case-control study was conducted among men aged 40-70 years in order to determine whether exercising for two or more hours per week (the "exposure") decreases the likelihood of heart attack (the "outcome"). The case group was comprised of 1,000 men who had recently had a heart attack. Among the cases, 396 reported that they had regularly exercised for two or more hours per week prior to their heart attack. The control group was comprised of 1,000 individuals who never had a heart attack. Among the controls, 562 reported that they exercised regularly.

a. Draw the two-by-two table for these data.

b. Using these data, calculate the association between regular exercise (two or more hours per week) and heart attack.

c. Please interpret/translate the association you calculated in part b into words. In addition, how would you describe the strength/magnitude and direction of this association?