Skippy Quadcopters plans to sell a standard quadcopter (toy drone) for $65 and a deluxe quadcopter for $95. Skippy purchases the standard quadcopter for $55 and the deluxe quadcopter for $70. Management expects to sell two deluxe quadcopters for every three standard quadcopters. The company's monthly fixed expenses are $12,800. How many of each type of quadcopter must Skippy sell monthly to breakeven? To earn $11,200? First identify the formula to compute the sales in units at various levels of operating income using the contribution margin approach. (Abbreviations used: Avg. = average, and CM = contribution margin.) ( Fixed expenses + Operating income / Weighed-avg. CM per unit = Breakeven sales in units Next compute the weighted average contribution margin per unit. First identify the formula labels, then complete the calculations step by step. Deduct: Weighted average contribution margin per unit