<prompt> In a study of 200 smokers and 300 non- smokers were followed up over a period of 10 yrs to find out incidence of hypertension. Out of 200 smokers,60 developed hypertension, as compared to 600 non- smokers of which 30 developed hypertension . The risk ratio of the study:3303-Jan6  <response>: Relative Risk RISK RATIO is used to estimate risk of disease calculated as incidence of that disease with exposure to a factorRelative Risk RR - Incidence among exposed Incidence among non-exposedIn the given question, 200 smokers 300 non-smokers were followed up over a period of 10 yrs to find out incidence of hypertension,Out of 200 smokers, 60 developed hypertension, thus Iexp 60 200 × 1000 300And, out of 600 non-smokers, 30 developed hypertension, thus Inon-exp a 30 600 ×1000 50 30050 6 