Exercise 5-4A Effect of inventory cost flow (FIFO, LIFO, and weighted average) on gross margin LO 5-1 The following information pertains to Mason Company for 2016: Beginning inventory Units purchased 90 units@$40 310 units@$45 Ending inventory consisted of 30 units Mason sold 370 units at $90 each. All purchases and sales were made with cash. Operating expenses amounted to $4,100. Required a. Compute the gross margin for Mason Company using the following cost flow assumptions: (1) FiFO, (2) LIFO, and (3) weighted average. What is the amount of net income using FIFO, LIFO, and weighted average? (Ignore income tax considerations.) b. c. Compute the amount of ending inventory using (1) FIFO, (2) LIFO, and (3) weighted average