Xr12-33 A random sample of American adults was asked whether or not they smoked cigarettes. Those who responded affirmatively were asked how many cigarettes they smoked per day. Assuming that there are 50 million American adults who smoke, estimate with 95% confidence the number of cigarettes smoked per day in the United States. (Adapted from the Statistical Abstract of the United States, 2009, Table 196 and Bloomberg News.)