Please assist.

\fAn 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 680, 000 Gross margin 300,000 Selling and administrative expenses Selling $110, 000 Administration 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