Calculate the gross profit percentage for the following information

Sellall Department Stores reported the following amounts in its adjusted trial balance prepared as of its December 31 year-end: Administrative Expenses, $2,400; Cost of Goods Sold, $22,728; Income Tax Expense, $3,000; Interest Expense, $1,600; Interest Revenue, $200; General Expenses, $2,600; Sales Revenue, $42,000; Sales Discounts, $2,200; Sales Returns and Allowances, $1,920; and Delivery (freight-out) Expense, $300.