3. A study showed that one factor that strongly correlates with student academic success is the number of books that the family has in their home. Researchers randomly selected 100 students and measured their academic success as well as counted the number of books their family has in their home. a. Is this an observational study or an experiment? Justify your answer.

b. What are the explanatory and response variables?

c. Explain clearly why such a study cannot establish a cause-and-effect relationship. Suggest a variable that may be confounded with number of books that the family have in their home