Radon gas exposure has been a suggestive of lung cancer in many patients. According to the information, some quantitative information can be gathered from the patients\' data in the hospital. Prevalance of a disease can be represented as the total number of individuals suffered from the diesease in a geographical area during a span of time. Thus, the calculations can be made as below: 1. The prevalence of cancer in those exposed to radon and in those who did not have exposure to radon: Number of individuals exposed to radon: 544 Number of individuals not exposed to radon: 177 Thus, a) Prevalance of radon exposed individuals : 544/911 or 0.597 or 59.7%. b) Prevalance of non-radon exposed patients: 177/911 or 0.194 or 19.4%. 2. The prevalence of exposure in those who had cancer and in those who did not have cancer: The total number of individuals who had cancer : 410 Number of individuals who were exposed and had cancer : 410-177 or 233. Number of individuals not exposed and had cancer = 177 Number of individuals who had not developed cancer but exposed to radon = 544-410 or 134 Thus, a) Prevalance of exposure in those who had cancer = Number of exposed individuals/ total number of positive cases or 233/410 i.e. 0.568 or 56.8% b) Prevalance of exposure in those who did not have cnacer: 134/410 or 0.326 or 32.6%. Solution Radon gas exposure has been a suggestive of lung cancer in many patients. According to the information, some quantitative information can be gathered from the patients\' data in the hospital. Prevalance of a disease can be represented as the total number of individuals suffered from the diesease in a geographical area during a span of time. Thus, the calculations can be made as below: 1. The prevalence of cancer in those exposed to radon and in those who did not have exposure to radon: Number of individuals exposed to radon: 544 Number of individuals not exposed to radon: 177 Thus, a) Prevalance of radon exposed individuals : 544/911 or 0.597 or 59.7%. b) Prevalance of non-radon exposed patients: 177/911 or 0.194 or 19.4%. 2. The prevalence of exposure in those who had cancer and in those who did not have cancer: The total number of individuals who had cancer : 410 Number of individuals who were exposed and had cancer : 410-177 or 233. Number of individuals not exposed and had cancer = 177 Number of individuals who had not developed cancer but exposed to radon = 544-410 or 134 Thus, a) Prevalance of exposure in those who had cancer = Number of exposed individuals/ total number of positive cases or 233/410 i.e. 0.568 or 56.8% b) Prevalance of exposure in those who did not have cnacer: 134/410 or 0.326 or 32.6%..