Redding Bookstore had 1020 units on hand at January 1, costing $ 9 each. Purchases and sales during the month of January were as follows: Date Jan. 17 25 29 7 Purchases Sales 740 @ $ 14 600 a $ 10 600 @ $8 400 @ $ 16 Redding does not maintain perpetual inventory records. According to a physical count, 1,080 units were on hand at January 31. Required: Calculate the cost of the inventory at January 31, under the FIFO-Lifo-and Simple Average method is and also calculate the COGS for January under each method. You must show how you calculate each number