Expert Q&A In Marystownr the risk of lung cancer over a 10 year period in smokers was 85 cases per 1000 people, in non smokers was 15 cases per 1,000 people and in the total population was 37 cases per 1000 people. For this 10 year period in Marystown, the population risk difference in reference to smoking as a cause of lung cancer was ? cases per 1000 people. Give your answer to the nearest single digit. Done