Helpful Hardware sells windows ( 80% of sales) and doors ( 20% of sales). The selling price of each window is $400 and of each door is $1,000. The variable cost of each window is $250 and of each door is $700. Fixed costs are $1,440,000. The break-even point in units using the weighted-average contribution margin is: Multiple Choice 8,000 units. 3,200 units. 12,000 unlts. 5,334 units. 6,858 units