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 $ 171 $ 78 $604,500 Required Determine the following: a. Contribution margin per unit. Contribution margin per unit b. Number of units that Ender must sell to break even. Break-even in units c. Sales level in units that Ender must reach to earn a profit of $186,000. Sales in units d. Determine the margin of safety in units, sales dollars, and as a percentage. (Round "Percentage" answer to 1 decimal place (i.e., 0.234 should be entered as 23.4).) Units Sales Percentage Margin of safety