Mandy Company uses a perpetual inventory system. It recorded the following information for January. Beginning inventory of 50 units at $120 per unit. Purchased 60 units at $130 per unit Sold 40 units at $200 per unit Purchased 100 units at $150 per unit Returned 30 units purchased on Jan 10 Sold 80 units at $220 per unit Jan 1 Jan 3 Jan 5 Jan 10 Jan 12 Jan 20 Questions (a) Compute the cost of goods sold and ending inventory cost under FIFO method and under weighted average method. You have to show the inventory movements and balance for each transaction. Round per unit cost to four decimal points and total cost to 2 decimal points for the weighted average method. (b) Compute the gross profit under FIFO method and under weighted average method. Explain why the gross profit differs when the company uses different inventory methods