Assume sales of $11000, variable costs of $7000, and fixed costs of $2800. Calculate contribution margin and operating income. Contribution margin = $4000; Operating income = $1200 Contribution margin = $6800; Operating income =$1200 Contribution margin = $8200; Operating income = $1200 Contribution margin = $8000; Operating income = $1200 Save for Later Attempts: 0 of 1 used