This is also given Exercise. Suppose that an observational study showed that students who got at least seven hours of sleep performed better on exams than students who didn't. Which of the following are possible confounding variables, and which are not? Explain why in each case.
a. Number of courses the student took that term.
b. Weight of the student.
c. Number of hours the student spent partying in a typical week.
Exercise
Suppose that an observational study showed that students who got at least 7 hours of sleep performed better on exams than students who got less than 7 hours of sleep. Which of the following are possible confounding variables, and which are not? Explain why in each case.
a. Number of courses the student took that term.
b. Weight of the student.
c. Number of hours the student spent partying in a typical week.