Let’s explore the relationship between marginal and average a little more. Suppose your grade in your economics class is composed of 10 quizzes of equal weight. You start off the semester well, then your grades start to slip a little, but then you get back into the swing of things, your grades pick up, and you finish off the semester with a bang. Your 10 quiz grades, in order, are: 82, 74, 68, 72, 77, 83, 86, 88, 90, and 100. Graph your marginal grades, along with your average grade, after each quiz. What do you notice about the relationship between marginal and averages? Your grades start improving with your fourth quiz grade; does your average also start increasing with your fourth quiz grade? Why or why not?