Final answer:
In a perfectly competitive labor market, the wage should equal the value of the marginal product of labor. If the product price is $12 and the marginal product is 3 units, then the wage for the last worker employed must be $36, calculated as 3 units × $12/unit.
Step-by-step explanation:
The wage in a perfectly competitive labor market is determined by the value of the marginal product of labor. Based on the given information, where the marginal product of the last worker is 3 units and the product price is $12, we can calculate the value of the marginal product by multiplying these two figures. So, the value of the marginal product is 3 units × $12/unit = $36.In a perfectly competitive labor market, a profit-maximizing firm will hire workers up to the point where the wage equals the value of the marginal product of labor. Therefore, if the last worker's marginal product is 3 units and the product price is $12, then the wage must be $36 for the last worker employed. This is because the firm would not want to pay more in wages than the additional revenue generated by the last worker, which is the value of their marginal product.