Table 7.1 presents the cost schedule for David's Production. If David produces three pencils, David's average variable costs are: Labor Number of Fixed Variable Average Marginal of Pencils Cost cost variable cost cost 0 $100 $100 $10 2 2 $100 $15 3 W $100 $20 4 A $6 Table 7.1 $120 $6.66 $80 $0