having trouble finding the FIFO, LIFO, and average-cost. need the ending inventory anf costs of goods sold for all three.

Splish Brothers Inc. had a beginning inventory of 135 units of Product RST at a cost of $ 7 per unit. During the year, purchases were: Feb. 20 650 units at $8 Aug. 12 420 units at $10 May 5 500 units at $9 Dec. 8 135 units at $11 Splish Brothers uses a periodic inventory system. Sales totaled 1520 units