<prompt> TATA memorial hospital conducted a cohort study on 7000 subjects who were smokers over a ten-year period found 70 subjects developed lung cancer. Concurrent evaluation of general population in the catchment area of hospital, out of 7000 non-smoker subjects only 7 developed lung cancer. The RR for developing lung cancer is1101000.1  <response>: TATA memorial hospital conducted a cohort study on 7000 subjects who were smokers over a tenyear period found 70 subjects developed lung cancer,Thus, Iexp × 1000 10 per thousandAlso, concurrent evaluation of general population in the catchment area of hospital, out of 7000 non-smoker subjects only 7 developed lung cancer,Thus, Inon-exp × 1000 1 per 1000Therefore, RR 10 per 1000 1 per 1000 10 