Questionnaires were mailed to 5,000 people who were selected randomly. Each person was asked to list age, sex, smoking habits, and respiratory symptoms during the preceding seven days. About 80% of the questionnaires were completed and returned, making the final completed sample of 4,000.
There were 1,100 total smokers in the sample. There were 1,000 respondents who had respiratory symptoms. About 700 of the respondents reported having upper respiratory symptoms and also smoked. There were 2,600 respondents who neither smoked nor had any respiratory symptoms. But there were 400 who smoked but had no respiratory symptoms.
Calculate the odds ratio of the disease and exposure. Be sure to provide the correct interpretation of your results.