Mathias Corporation manufactures and sells wire rakes. The rakes sell for $20 each. Information about the companys costs is as follows: Variable Variable manufacturing cost per unit $ 9 Variable selling and administrative cost per unit $ 4 Fixed manufacturing overhead per month $ 250.000 Fixed selling and administrative cost per month $ 350.000 a. Determine the companys monthly break-even point in units. b. Determine the sales volume (in dollars) required for a monthly operating income of $100,000. c. Estimate the amount by which monthly operating income will increase if the company anticipates a $200,000 increase in monthly sales volume.