Distinguishing Correlation and Causation Practice Test

A college health center found that students who reported more cups of water per day tended to report fewer headaches per month (a negative correlation). The data came from a voluntary questionnaire; students were not assigned water intake amounts. Which statement best describes what the data show?

A fitness app analyzed its users and found a negative correlation between daily minutes of exercise and resting heart rate: users who exercised more tended to have lower resting heart rates. The app only used existing user data and did not assign exercise levels. Which statement best describes what the data show?