Answer:
$100
Explanation:
Total cost if he installs seven systems = $300
Total cost if he installs eight systems = $400
Therefore, the marginal cost of installing 8th system is the difference between the total cost of installing eight systems and the total cost of installing seven systems.
Marginal cost of installing 8th system:
= Total cost of installing 8 systems - Total cost of installing 7 systems
= $400 - $300
= $100
The profit maximization conditions says that the marginal cost must be equal to the marginal revenue.
Hence,
William will install eight systems per day only if the eight customer is willing to pay at least $100.
