An income statement for Sam's Bookstore for the first quarter of the year is presented below: Sam's Bookstore Income Statement. For Quarter Ended March 31. Sales $ 900,000 Cost of goods sold 640,000 Gross margin 260,000 Selling and administrative expenses Selling $ 102,000 Administrative 108,000 210,000 Net operating income $ 50,000 On average, a book sells for $60. Variable selling expenses are $5 per book with the remaining selling expenses being fixed. The variable administrative expenses are 4% of sales with the remainder being fixed. The contribution margin for Sam's Bookstore for the first quarter is: