12. In this chapter we have seen that the PPF could be bowed-out or a straight line.

a. Provide an example of two goods where the PPF would be bowed-out.

b. Provide an example of two goods where the PPF would be a straight line.

c. It also turns out that the PPF can bow in. This occurs when the production process produces economies of scale, which means that it is possible to make more of each good as production expands. Can you think of two goods where the PPF would be bowed-in?