posted by Bill .
Suppose that a firm has only one variable input, labor, and firm output is zero when labor is zero. When the firm hires 6 workers it produces 90 units of output. Fixed cost of production are $6 and the variable cost per unit of labor is $10. The marginal product of the seventh unit of labor is 4. Given this information, what is the total cost of production when the firm hires 7 workers?
$66, $76, $906, $946