Information concerning a product produced by Ender Company appears here: 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 $240,000. d. Determine the margin of safety in units, sales dollars, and as a percentage. Complete this question by entering your answers in the tabs below. 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).)