In testing a treatment designed to reduce driver aggression in the United States, the original plan was to use a sample of 500 drivers randomly selected throughout the country. The program managers know that they would get a biased sample if they limit their study to drivers in New York City, so they planned to compensate for that bias by using a larger sample of 3000 drivers in New York City?
Determine whether the study is an experiment or an observational study, and then identify a major problem with the study.