a) Draw a Production Possibility Frontier for the production of hamburgers and milkshakes at a hamburger restaurant (which faces increasing marginal opportunity costs).
b) Indicate a point 'X' on your diagram that is attainable, but is inefficient.
c) Describe a scenario in which the restaurant might be producing at point 'X', and justify your answer.
d) Explain the real-world reasoning behind why the production possibility frontier would be likely to have the shape that you have drawn.