Rally Quadcopters plans to sell a standard quadcopter (toy drone) for $54 and a deluxe quadcopter for $64. Rally purchases the standard quadcopter for $34 and the deluxe quadcopter for $39. Management expects to sell two deluxe quadcopters for every three standard quadcopters. The company's monthly fixed expenses are $20,900. How many of each type of quadcopter must Rally sell monthly to breakeven? To earn $11,000? 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.) Breakeven sales in units Contribution margin ratio Fixed expenses Operating income Units sold Variable expenses Weighed-avg. CM per unit