Blair collected data about the grades that her friends earned on a recent test (y) and how long each of them studied (x). Why is the number of minutes spent studying the x-variable in this situation? The number of minutes spent studying is the , x, -variable because it is likely to have an effect on the number of minutes spent working on the test.

The number of minutes spent studying is the , x, -variable because it is likely to have an effect on the grade earned on the test.

The number of minutes spent studying is the , x, -variable because it is the dependent variable.

The number of minutes spent studying is the x-variable because it is chosen at random.