Laker Company reported the following January purchases and sales data for its only product. For specific identification, ending inventory consists of 400 units from the January 30 purchase, 5 units from the January 20 purchase, and 15 units from beginning inventory. Assume the perpetual inventory system is used. Required: 1. Compute gross profit for the month of January for Laker Company for the four inventory methods. 2. Which method ylelds the highest gross profit? 3. Does gross profit using weighted average fall between that using FIFO and LIFO? 4. If costs were rising instead of falling, which method would yield the highest gross profit