The following information pertains to Porter Company for 2011. Beginning inventory 70 units @ $13 Units purchased 280 units @ $18 Ending inventory consisted of 30 units. Porter sold 320 units at $30 each. All purchased and sales were made with cash. Determine the cash flow from operating activities, using each of the three cost flow assumptions,LIFO, FIFO, and weighted average. Ignore the effect of income taxes. Explain why these cash flows have no differences.