In the United States, there has historically been a strong relationship between smoking and education, with well-educated people
less likely to smoke. To examine whether this pattern has changed, a sample of 459 men was selected at random from those who had visited a health center for a routine check-up over the course of the past year. Education is classified into three categories corresponding to the highest level of education achieved, and smoking status is classified into four categories. Smoking Status Education Nonsmoker Former Moderate Heavy Total High School 56 54 41 36 187 College 37 43 27 32 139 Graduate School 53 28 36 16 133 Total 146 125 104 84 459 The proportion of men with a high school education that are current or former smokers is a) 0.12. b) 0.30. c) 0.78. d) 0.70.
The proportion of men with a high school education that are current or former smokers is given by the sum of former, moderate and heavy smokers with a high school education divided by the total number of men with a high school education sampled:
