What am I missing and what is correct?

Required: 1. Compute cost of goods available for sale and the number of units available for sale. Answer is complete and correct. 2. Compute the number of units in ending inventory. Answer is complete and correct. 3. Compute the cost assigned to ending inventory using (a) FIFO, (b) LIFO, (c) weighted average, and ( d ) specific identification. (For specific identification, units sold consist of 600 units from beginning inventory, 300 from the February 10 purchase, 200 from the March 13 purchase, 50 from the August 21 purchase, and 250 from the September 5 purchase.) 4. Compute gross profit earned by the company for each of the four costing methods. (Round your average cost per unit to 2 decimal places.)