PQR Supermarket purchases a specific type of cereal throughout the month of February 2023. The purchase and sales data for the month are as follows: February 1st: Beginning inventory - 100 units at $5 each February 10th: Purchase - 200 units at $6 each February 15th: Purchase - 150 units at $7 each February 20th: Purchase - 180 units at $8 each February 25th: Sales - 300 units Calculate the cost of goods sold (COGS) and the ending inventory using the weighted average method as of February 28th, 2023. (2.5 marks)