An experiment was conducted to test whether aspirin improves performance. In the experiment, students at Montgomery College were given aspirin and students at Frederick College we given a sugar pill...

An experiment was conducted to test whether aspirin improves performance. In the experiment, students at Montgomery College were given aspirin and students at Frederick College we given a sugar pill (but they were told that it was aspirin) before their Psychology classes. The students who were given the aspirin performed better on the exams (average score 94%) than the subjects who were given the sugar pill (average score 74%).

Question: What is the dependent variable in this experiment?  Explain why.