For each example, identify whether the study was an observational study or a randomized experiment. Briefly justify your answers.

1. A group of students were randomly assigned to take either an online statistics course or a traditional lecture statistics course. The two methods were compared by giving the same final exam in both courses.
2. A group of smokers and non-smokers attending a particular clinic were asked to come in for a physical exam every 5 years to monitor their health.
3. CEOs of major corporations were compared with other employees to identify if CEOs were more likely to be the first-born child in their families than other employees.