Which of the following books serves as the direct base for preparing a Trial Balance?

Based on a plant and equipment cost account, the original cost of an asset disposed of was $27,700. The business made a profit on disposal of $4,370 after accumulated depreciation of $6,200 was charged. How much should be included as cash proceeds in the statement of cash flows?

A business uses the FIFO method for inventory valuation. During a period of constantly rising prices, the business decides to switch to the Weighted Average Cost (AVCO) method. What is the likely effect of this change on the Gross Profit Margin and the Closing Inventory value?