Michelle's Marbles generated $102,300 in total sales for the month of September. Her total variable costs were just $46,500, leaving her with total contribution margin of $55,800. The selling price per unit of marbles (a small bag is considered a unit) is $11. How many units did Michelle sell that month? Number of units sold units What was her variable cost per unit? Variable costs per unit What was her contribution margin per unit? Contribution margin 5 perunit