i know this is not exactly where you post help questions but i really need it. heres my questions. I just started learning microeconomics and i am already confused. I was reading production possibility frontiers and how marginal cost and marginal benefit are related. I know that marginal cost is the slope of the PPF, and by doing this i get graph a marginal cost curve, but how do i calculate marginal benefits. I'll put some numbers. Point A is (0, 15) and Point B is (1,14) Marginal cost= 14-15/1-0 = -1 Now how do i find marginal benefit at these two points. I am trying to draw the marginal benefit curve. If you need more points, then tell me and i will post them.