Problem 4.. The contour graph below shows the daily profit of a company (in thousands of dollars) as a function of the number of units of materials purchased k and number of units of labor used l. (a) Sketch the section where k=16 is held constant. Sketch it carefully. What happens to the profit when l is close to 0 ? What happens to the profit when l is large? At what value of l is the profit a maximum and about what is this maximum profit? (b) Approximately what are the values of l and k that maximize the profit? What is the corresponding profit? Suppose one unit of materials costs $400 and one unit of labor costs $100 and the firm has a budget of $1600. If the firm spends its whole budget, the values of k and l will satisfy the equation 400k+100l=1600 This is called a budget constraint equation. (c) Draw the budget constraint line on the contour graph below. (Draw it accurately using a straight edge.) (d) Does the firm have enough budget to achieve the maximum profit level you found in part (b)? (e) What is the maximum profit the firm can realize given their budget constraint? What are the corresponding values of k and l