Would you mind showing me how to calculate the gross margin ratio, please

(The following information applies to the questions displayed below.) The following unadjusted trial balance is prepared at fiscal year-end for Nelson Comp NELSON COMPANY Unadjusted Trial Balance January 31 , 2017 Debit Credit Cash $ 1,000 Merchandise inventory 12,500 Store supplies 5, 800 Prepaid insurance 2,400 Store equipment 42,900 Accumulated depreciation store equipment $ 15,250 Accounts payable 10,000 Common stock 5,000 Retained earnings 27,000 Dividends 2,200 Sales 111,950 Sales discounts 2,000 sales returns and allowances 2,200 Cost of goods sold 38,400 Depreciation expense-store equipment salaries expense 35,000 Insurance expense Rent expense 15,000 Store supplies expense Advertising expense 9, 800 Totals $169,200 $169,200 ES