Suppose that a firm's only variable input is labor. The firm increases the number of employees from four to five, thereby causing weekly output to rise by five units and total costs to increase from $3,500 per week to $3,800 per week. What is the marginal product of the fifth worker? 5 units. (Your answer should be a whole number.) What is the weekly wage rate earned by the fifth worker? $ . (Your answer should be rounded to the nearest dollar.)