Answer:
The marginal cost of each screen is $10,000.
Step-by-step explanation:
Giving the following information:
They discovered that installation costs at stores with four screens were $60,000 but were $80,000 at stores with six terminals.
The marginal cost of each screen is $10,000. And the fixed costs are $20,000.
Six screens= 20000 + 10000*6= $80,000