Final answer:
A graph of variable cost starts at the origin and slopes upward, reflecting the nature of variable costs which increase with output. Different types of costs such as average cost, marginal cost, and average variable cost can appear almost flat when graphed on the same axis as total costs, due to their much smaller numerical values.
Step-by-step explanation:
The graph for a variable cost depicts the costs that vary with the level of output. By definition, variable costs start at zero when the output is zero and increase as output increases. Therefore, the correct answer for a graph of variable cost is: it starts at the origin and slopes upward. This is because there are no costs when there is no production, and the costs increase in proportion to the level of production.
When graphing costs, it is important to note that total cost, fixed cost, and variable cost lines on the same graph can lead to misunderstandings because different types of costs have very different magnitudes. For example, the average cost of producing 40 haircuts at a total cost of $320 would be calculated as $320/40, resulting in $8 per haircut. If both total cost and average cost were graphed on the same axes, the average cost line would appear almost flat in comparison to the total cost, as it represents a much smaller numerical value with a different scale.
In the context of cost graphs:
- If marginal cost, average cost, and average variable cost were graphed on the same axis as the total costs, these lines would hardly be visible or would appear almost flat compared to the values for total cost. This is due to the relatively smaller scale of these costs compared to total cost values that can be significantly higher.