a. To calculate the profit of the firm, we need to first find the total revenue and total cost.
Total revenue = Average revenue * Quantity = $10 * 100 = $1000
Total cost = Average total cost * Quantity = $8 * 100 = $800
Profit = Total revenue - Total cost = $1000 - $800 = $200
Therefore, the profit of the firm is $200.
b. The marginal cost of a firm can be found by calculating the change in total cost when output increases by one unit.
Marginal cost = Change in total cost / Change in quantity
In this case, since the firm is producing 100 units, any change in quantity will result in a change in total cost. Therefore, the marginal cost is equal to the average total cost, which is $8.
c. Average variable cost (AVC) represents the cost per unit of variable inputs used to produce a certain level of output. It is calculated by dividing total variable cost by the quantity of output.
Total variable cost = Total cost - Fixed costs = $800 - $200 = $600
Average variable cost = Total variable cost / Quantity = $600 / 100 = $6
Therefore, the average variable cost for this firm is $6.
d. The efficient scale of a firm refers to the output level at which the firm achieves its lowest average total cost. In a competitive market, the efficient scale typically occurs at the output level where the firm has reached its minimum efficient scale (MES).
Based on the given information, we do not have enough information to determine whether the efficient scale of the firm is more than, less than, or exactly 100 units. The information provided only indicates that the firm is currently producing 100 units, but it does not tell us whether this is the most efficient level of production for the firm.