Answer:
Option (c) Marginal cost of fifth unit = $20
Explanation:
According to the scenario, computation of the given data are as follows:
1)
Option (b) : Marginal cost is the change in the total cost of firm due to one unit change in output.
We can calculate the marginal cost by using following formula :
Marginal cost = Total cost ÷ Quantity
2)
Marginal cost of fifth unit = Total cost at unit 5 - total cost at unit 4
= $160 - $140
= $20