An economist conducts a nationwide survey to study the financial perceptions of US adults. Specifically, he asks a random sample of 1,000 US adults: “Financially, are you doing OK or are you struggling to get by?” The results of the survey show that 829 of the 1,000 participants said they are doing OK. (a) Construct a 95% confidence interval for the proportion of US adults who would say they are doing OK.

(b) Shortly thereafter, a similar study is conducted in Mexico with the intention of constructing a 95% confidence interval for the proportion of Mexican adults who would say they are doing OK. What is the smallest sample size that can be used to guarantee that the margin of error will be less than or equal to 0.01?