help!!!

method is perpetual.

Required: 1. Compute cost of goods available for sale and the number of units available for sale: 2. Compute the number of units in ending inventory. 4. Compute gross profit eamed by the company for each of the four costing methods. For specific identification. units sold include 50 units from beginning inventory, 180 units from the March 5 purchase, 30 units from the March 18 purchase, and 70 units from the March 25 purchase. (Round weighted average cost per unit to two decimals ond final answers to nearest whole dollor.)