Intermediate Microeconomics and Its Application 12th Edition by Walter Nicholson,Christopher Snyder

Exercise 21

Suppose that there are to be 10 quizzes in your economics course. You have scored 80 on every one of the first 5 quizzes.
1. What will happen to your average for the course if your grade falls to 60 on each of the next 2 quizzes?
2. What will you have to score on the final 3 quizzes in the course to get your average back to 80?
3. Explain how this example illustrates the relationship between average and marginal costs studied in this section.