You have been hired as an economic consultant to a firm that uses labour and plastic to produce lawn chairs. Your task is to compute the short-run marginal cost of producing chairs at the current level of production (20 workers and 100 chairs per day). Each chair requires $7.5 worth of plastic. The manager has given you control of the production line for the next 3 days, so you can experiment by varying the number of workers on the production line. The daily wage is $130. Describe your strategy for computing the marginal cost of a chair and construct a numerical example under which the marginal cost is $25. Make assumptions to help you answering this question.

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