Juan realizes that if he studies an extra hour for his test, he will score five points higher. For each extra hour spent studying, he is getting one hour less sleep. When deciding whether to spend an additional hour studying or sleeping, Juan is engaged in what economic activity?
Marginal analysis is what business do when faced a desicion, putting the benefits of the desicion agaisnt the cost, when they meet the most profitable spot between cost and benefits that´s where they land.