billion people is emerging as the world's biggest cigarette market. In fact, China's cigarette industry is the central government's largest source of tax revenue. To better understand Chinese smokers and the potential public health disaster they represent, door-to-door interviews of 3,423 men and 3,593 women were conducted in the Minhang District, a suburb of 500,000 people near Shanghai. The study concluded that "people in China, despite their modest incomes, are willing to spend an average of 60 percent of personal income and 17 percent of household income to buy cigarettes" (Newark Star-Ledger, Oct. 19,1995).

a. Identify the population that was sampled.

b. How large was the sample size?

c. The study made inferences about what population?

d. Explain why different answers to parts a and c might affect the reliability of the study's conclusions.