Nancy's Marbles generated $65,400 in total sales for the month of September. Her total variable costs were just $43,600, leaving her with total contribution margin of $21,800. The selling price per unit of marbles (a small bag is considered a unit) is $6. How many units did Nancy sell that month? Number of units sold What was her variable cost per unit? Variable costs. $ What was her contribution margin per unit? Contribution margin $ units per unit per unit