Information concerning a product produced by Ender Company appears here: $ 166 $ 79 Sales price per unit Variable cost per unit Total annual fixed manufacturing and operating costs $591,600 Required Determine the following: a. Contribution margin per unit. Contribution margin $ 87 per unit b. Number of units that Ender must sell to break even. 6,800 c. Sales level in units that Ender must reach to earn a profit of $139,200. d. Determine the margin of safety in units, sales dollars, and as a percentage. (Round "Percentage" answer to 1 decimal place (i.. 0.234 should be entered as 23.4).) Units Sales Porcentage Margin of safety