Paid to quit In an effort to reduce health care costs, General Motors
sponsored a study to help employees stop smoking. In the study, 439
volunteer subjects were randomly assigned to receive up to $750 for
quitting for a year, while the other 439 volunteer subjects were simply
encouraged to use traditional methods to stop smoking. After one year,
people who had the financial incentive were 3 times more likely to have
quit smoking.
(a) What is the statistical question that the researchers were trying to
answer?
(b) Identify the population and sample.
(c) Is this an observational study or an experiment? Explain.