The following information is available for Flip Company: Beginning inventory 600 units at $4 First purchase 900 units at $6 Second purchase 500 units at $7.20 Assume that Flip uses a periodic inventory system and that there are 700 units left at the end of the month. Instructions: Compute the cost of ending inventory and Cost of Good Sold under the (a) FIFO method. (b) LIFO method. (c) Average-cost method