In the short-run, we assume that capital is a fixed input and labor is a variable input, so the firm can increase output only by increasing the amount of labor it uses. In the short-run, the firm's production function is q = f(L, K), q= 4LK+312 - 313. where q is output, L is workers, and K is the fixed number of units of capital. What is the marginal product of labor as a function of L and K? MPL =. (Properly format your expression using the tools in the palette. Hover over tools to see keyboard shortcuts. E.g., a superscript can be created with the ^ character.) For example, if L =7 and K = 29, then the marginal product of labor equals MPL =. (Enter a numeric response using an integer.) If L = 10 and K = 29, then the marginal product of labor equals MPL = . (Enter a numeric response using an integer.)