I need help understanding where I am off

Required information [The following information applies to the questions displayed below.] The following are the transactions for the month of July. Required: . Calculate cost of goods available for sale and ending inventory under FIFO. Assume a periodic inventory system is used . Calculate sales, cost of goods sold, and gross profit, under FIFO. Assume a periodic inventory system is used. Complete this question by entering your answers in the tabs below. Calculate cost of goods available for sale and ending inventory under FIFO. Assume a periodic inventory system is used