Answer:
                               FIFO:            LIFO:
Ending Inventory: 1, 890           1,080
COGS                    6,400           7,210
Explanation:
      (1)  370 units at $4 =  1,480
      (2) 470 units at $6 = 2,820
      (3) 570 units at $7 =<u> 3,990  </u>
<em>Total:</em> 1,410 units <em>Cost: </em>  8,290
FIFO:
The first units are sold while the last are part of ending inventory:
The 270 units of ending inventory will be frm the third purchase.
270 x $7 = 1,890
The COGS will be the difference between the cost of goods available and ending inventory: 8,290 - 1,890 = 6,400
LIFO:
The last units are sold while the first are part of ending inventory
The 270 units of EI will be taken from the first row
270 units x $4 = 1,080
COGS: 8,290 - 1,080 = 7,210