Question: Are you feeling stressed? (4.1) A Gallup Poll asked whether people experienced stress "a lot of the day yesterday." About 41 percent said they did. Gallup's report said, "Results are based on telephone interviews conducted ... Jan. 1-Dec. 31, 2012, with a random sample of 353,564 adults aged 18 and older."5
(a) Identify the population and the sample.
(b) Explain how undercoverage could lead to bias in this survey.