Is a specialty popcorn store. it offers two varieties of popcorn: plain and flavored. the flavors range from caramel popcorn to dark chocolate drizzled popcorn to white cheddar popcorn. the plain popcorn sells for $ 2.00 per box and costs $ 0.80 per box to make. the flavored popcorn sells for $ 4.00 per box and costs $ 2.50 per box to make. popped exclamation mark has fixed costs per month of $ 3 comma 240. popped exclamation mark sells 1 box of plain popcorn for every 4 boxes of flavored popcorn. how many boxes of plain popcorn and how many boxes of flavored popcorn must popped exclamation mark sell each month to break even? 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.) ( fixed expenses + operating income ) / weighed-avg. cm per unit = breakeven sales in units determine the weighted-average contribution margin per unit by identifying the formula labels and then completing the calculations step by step. sale price per unit deduct: fixed expenses variable expense per unit contribution margin per unit contribution margin weighted average contribution margin per unit