investigate the effects of smoking and lung cancer development in men for a number of professions.

investigate the effects of smoking and lung cancer development in men for a number of professions.

Data summarizes a study of men in 25 occupational groups in England. Two indices are presented for each occupational group. The smoking index is the ratio of the average number of cigarettes smoked per day by men in the particular occupational group to the average number of cigarettes smoked per day by all men. The mortality index is the ratio of the rate of deaths from lung cancer among men in the particular occupational group to the rate of deaths from lung cancer among all men.