Guthrie Industries manufactures and sells dog collars. The collars sell for $12 each. Information about the company's costs is as follows. Variable manufacturing cost per unit Variable selling and administrative cost per unit Fixed manufacturing overhead per month Fixed selling and administrative cost per month a. Determine the company's monthly break-even point in units. 1 $ 250,000 200,000 b. Determine the sales volume (in dollars) required for a monthly operating income of $900,000. c. Compute the company's margin of safety if its current monthly sales level is $1,400,000. d. Estimate the amount by which monthly operating income will increase if Guthrie anticipates a $60,000 increase in monthly sales volume. a. Break-even point b. Sales revenue c. Margin of safety d. Increase in operating income units