please explain every step

Complete this question by entering your answers in the tabs below. Using weighted-average cost, calculate sales revenue, and gross profit. (Round answers to 2 decimal places.) Complete this question by entering your answers in the tabs below. Using LIFC alculate sales revenue, and gross profit. Using FIFO, calculate sales revenue, and gross profit. Using FIFO, calculate ending inventory, cost of goods sold. Complete this question by entering your answers in the tabs below. Using LFO, calculate ending inventory, cost of goods sold. etermine which method will result in higher profitability when inventory costs are declining. During the year, Triumph Incorporated has the following inventory transactions. For the entire year, the company sells 81 units of inventory for $30 each. Required: 1-a. \& b. Using FIFO, calculate ending inventory, cost of goods sold. 1-c t. Using FIFO, calculate sales revenue, and gross profit. 2-a \& b. Using LIFO, calculate ending inventory, cost of goods sold. 2- & d. Using LIFO, calculate sales revenue, and gross profit. 3-a \& b. Using weighted-average cost, calculate ending inventory, cost of goods sold. 3-c \& d. Using weighted-average cost, calculate sales revenue, and gross profit. 4. Determine which method will result in higher profitability when inventory costs are declining