Answer:
They must keep their marginal cost equal to their marginal revenue
Explanation:
The marginal cost of a product is the cost added by producing one additional product or service.
The marginal revenue is the additional revenue generated by increasing product or service sales by one unit.
Companies will do analysis of marginal cost to determine if the value of the product being produced is worth the marginal revenue gained by creating additional units of that good or service. You'll see this often with big companies that produce huge volumes of units, like nvidia creating graphics chips. They are attempting to maximize the profit while minimize the cost of production for their good or service.
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