Helpful Hardware sells windows $(80\%$ of sales$)$ and doors $(20\%$ of sales$).$ The selling price of each window is $$700$ and of each door is $$1,300.$ The variable cost of each window is $$475$ and of each door is $$1,000.$ Fixed costs are $$1,938,000.$ The break$-$even point in units using the weighted$-$average contribution margin is:Multiple Choice$01$:$13$:$545,600$ units$\mathrm{.}8,075$ units$\mathrm{.}15,600$ units.