A radio talk show host is interested in the proportion p of adults in his listening area who think the drinking age should be lowered to 18. To make this determination, he poses the following question to his listeners: "Do you think that the drinking age should be reduced to 18 in light of the fact that 18-year-olds are eligible for military service?" He asks listeners to phone in and vote "yes" if they agree the drinking age should be lowered and "no" if not. Of the 200 people who phoned in, 140 answered "yes." The standard error for the proportion p of those who phoned in and answered "yes" is: