If a student decides to study an extra hour for an exam and finds that their exam score increases significantly, what is the most likely cause of this increase in score?

The increase in the student's exam score after studying an extra hour can be explained by the concept of marginal benefit, which means the extra benefit gained from doing something a little more. In this case, the additional hour of study likely helped the student understand the material better, leading to improved performance on the exam. The effort put into studying is worth it if it results in a higher score, showing that the marginal benefit of studying exceeds the marginal cost of spending that extra hour. For example, if the student was initially scoring 70% and after studying more, they scored 85%, the extra study time provided a significant benefit. This illustrates how investing a little more time in preparation can lead to better outcomes in learning.