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 $980,000 Cost of goods sold Gross margin Selling and administrative expenses 680,000 300,000 Selling Administration $110,000 124,000 234,000 Net operating income $ 66,000 On average, a book sells for $70. Variable selling expenses are $4 per book with the remaining selling expenses being fixed. The variable administrative expenses are 3% of sales with the remainder being fixed. The cost formula for selling and administrative expenses with "X equal to the number of books sold is: Multiple Choice Y = $95,400 + $6.10X Y = $148,600 + $8.20X Y = $148,600 + $6.10X Y- $95,400 + $4.00x