A South African company that is selling mining and construction equipment is doing a roaring business, as evidenced by the numbers on the table below. Number of clients Total fixed costs Total variable cost Total costs Marginal costs 0 20000 0 20000 -------- 1000 20000 30000 -------- 30 2000 20000 50000 70000 --------- 3000 20000 ---------- 85000 15 4000 ----------- 85000 105000 20 5000 20000 110000 ------- 25 6000 20000 150000 170000 -------- 7000 20000 210000 230000 60 a) Fill in the missing figures on the table. (8) b) Use the final table to draw the new businesss total cost curves. (6) c) Use the answers for marginal costs to describe how they behave when the level of production changes. (6) d) Following the example provided above calculate and use the figures to plot the average costs (add 3 columns to the table) and the marginal costs on the same graph.