A business has inventory of material A of 400 units valued at $2.50 per unit September 1. During the month of September, the movements of material A were as follows: September 5, issue 250 units at $5.00 per unit September 10, receipt 500 units at $2.50 per unit September 15, issue 340 units at $5.50 per unit September 18, receipt 400 units at $2.70 per unit September 27, issue 600 units at $6.50 per unit a) Determine the cost of purchases, cost of issues, and the closing stock valuation using the FIFO method of stock valuation b) If expenses for the month of September was $15,550, what is Net Income?