A 2012 Gallup survey interviewed by phone a random sample of 474,195 U.S. adults. Participants were asked to describe their work status and to report their height and weight (to determine obesity based on a body mass index greater than 30). Gallup found 24.9% obese individuals among those interviewed who were employed (full-time or part-time by choice), compared with 28.6% obese individuals among those interviewed who were unemployed and looking for work.
What can you reasonably conclude from this survey?

Question

Quizplus · Accepted Answer

The survey provides a random sample of 474,195 U.S. adults, and reports the proportions of obesity among employed and unemployed individuals. Therefore, we can conclude that approximately 24.9% of American adults who are employed are obese compared with approximately 28.6% among those who are unemployed and looking for work. Option A is incorrect because the survey did not use a voluntary response sample, but instead used a random sample. Option B is incorrect because the sample size is large enough to provide statistical significance. Option D is incorrect because the survey did not ask about reading Gallup surveys, but instead solicited information about employment status and obesity.

A 2012 Gallup Survey Interviewed by Phone a Random Sample