Information concerning a product produced by Ender Company appears here: Sales price per unit Variable cost per unit Total annual fixed manufacturing and operating costs $ 161 76 $561,000 Required Determine the following: a. Contribution margin per unit. b. Number of units that Ender must sell to break even. c. Sales level in units that Ender must reach to earn a profit of $187,000. d. Determine the margin of safety in units, sales dollars, and as a percentage.