The periodic rate is a) an interest rate that changes over the term of the loan b) the interest rate you are charged for one payment period c) the apr multiplied by twelve d) the amount of time you have to pay your loan

In the short-run, marginal costs are equal to the change in variable costs as output changes. ( mc = change in variable cost / change in quantity) assume that capital is fixed in the short-run. (a) start with the equation for marginal cost and derive an equation that relates marginal cost of production to the cost and productivity of labor. (b) draw a standard looking short-run marginal cost curve and use the equation you derived to explain its shape.