A cement manufacturer has supplied the following data: | Tons of cement produced and sold Sales revenue Variable manufacturing expense Fixed manufacturing expense Variable selling and administrative expense Fixed selling and administrative expense Net operating income 270,000 $974,000 $231,000 $310,000 $158,600 $92,000 $182,400 The company's contribution margin ratio is closest to: Multiple Choice 18.7% 44.5% 60.0% 68.2%