University Store, Inc. is a major retailer of branded shirts for several nearby colleges. Operating income for the month of October is as follows: Sales revenue Cost of goods sold Gross profit Selling expenses Administrative expenses Operating income $800,000 370,000 $430,000 150,000 110,000 $170,000 Each shirt sells for $40. Variable selling expenses are $4 per shirt, and the remainder of the selling expenses are fixed. Variable administrative expenses are 8% of sales revenue, and the remainder of the administrative expenses are fixed. What is University Store's contribution margin for the month of October?