A cement manufacturer has supplied the following data:

Tons of cement produced and sold	285,000
Sales revenue	$989,000
Variable manufacturing expense	$234,000
Fixed manufacturing expense	$319,000
Variable selling and administrative expense	$181,380
Fixed selling and administrative expense	$95,000
Net operating income	$159,620

The company's contribution margin ratio is closest to:

44.1%

58.0%

67.7%

16.1%