2. Suppose a production possibilities frontier includes the following combinations: Cars Washing Machines 0 1,000 100 600 200 0 a . Graph the PPF, assuming that it has no curved segments. b. What is the cost of producing an additional car when 50 cars are being produced? C. What is the cost of producing an additional car when 150 cars are being produced? 3. Determine whether each of the following would cause the national economy's PPF to shift inward, outward, or not change at all: a. An increase in immigration b. An increase in the average length of annual vacations c. The average retirement age going from 67 to 60 d. The migration of skilled workers to another country