Final answer:
The graphing of average fixed cost (AFC) is not necessary when graphing average variable cost (AVC) and average total cost (ATC) because these costs are measured in different units.
Step-by-step explanation:
Total cost, fixed cost, and variable cost reflect different aspects of the cost of production over the entire quantity of output produced. On the other hand, marginal cost, average cost, and average variable cost are costs per unit. Since these costs are measured in different units ($ versus $ per unit of output), it would not make sense to include all of them on the same graph. Therefore, it is not necessary to include a graph of average fixed cost (AFC) when graphing average variable cost (AVC) and average total cost (ATC).