Hugo polled 100 randomly selected people to see if they had exercised that week and found that 85% said they had. Lily asked 400 randomly selected people the same question and found that 85% of them also responded that they had exercised that week.

For the same confidence level and sample proportion, the margin of error is proportional to 1/√n, where n is the sample size. Hugo’s sample of 100 is one-fourth the size of Lily’s 400, so his margin of error is √4 = 2 times as large. Therefore, choice A is correct: Hugo’s margin of error will be exactly 2 times Lily’s.

AI-written and checked against the verified answer.