please can provide explanation on the firm return of scale

4. (27 points) A firm uses labor, denoted by Z, and capital, denoted by k, to produce skateboards. The firm's production function is f(k, l) = ki . 12. The price of labor, denoted by w, and the price of capital, denoted by r, are both equal to $10. (a) (5) Does the firm exhibit constant return to scale, increasing return to scale or decreasing return to scale? Why? (b) (8) What input combination should be the firm use to produce q units of output? (c) (8) Derive the total, marginal, and average cost functions. W (d) (6) Draw graphs of the cost functions. Put total cost in one graph and marginal and average cost in another. Explain why the cost curves look the way they look