The beginning (opening) stock consists of 2,500 boxes at a unit cost of $28 each. Transactions: 1. On February 7, weekly sales of 1,000 boxes at a price of $40 each. 2. On February 9, purchase on credit of 2,000 boxes of boxes at a cost of $30 per box. 3. On February 14, weekly sale of 1,000 boxes on credit at a price of $40 each and 1,000 boxes on cash at the price of $39 each. 4. On February 16, cash purchase of 5,000 boxes of boxes at a cost of $27 per box. 5. On February 21, weekly sales of 1,250 boxes for cash at a price of $39 each and 2,000 boxes for credit at the price of $38 each. 6. On February 27, purchase on credit of 5,000 boxes of sheets at a cost of $29 per box. 7. On February 28, weekly sales of 4,000 boxes on credit at a price of $35 each and 2,250 boxes at cash at the price of $38 each. WORK TO DO : Please record the following transactions according to the periodic and permanent inventory systems and according to recognized cost determination methods. For each situation, please determine the cost of goods sold as well as gross margin.