Please help me with the ones i got wrong

Perpetual inventory using LIFO Beginning inventory, purchases, and sales data for DVD players are as follows: The business maintains a perpetual inventory system, costing by the last-in, first-out method. The business maintains a perpetual inventory system, costing by the lest-in, first-out method. Determine the cost of goods sold for each saie and the inventory balance after each sale, presenting the data in the form lilustrated in Exhibit 4. Under LIFO, if units are in inventory at two different costs, enter the units with the HIGHER unit cost first in the Cost of Goods Sold Unt Cost column and LOWER unit cost first in the inventory Unit Cost column