Calculate the missing numbers in the following situations. (Input all amounts as positive values.) a Invoice cost of merchandise purchases $ 43,000 $20,000 $ 15,250 Purchase discounts 1,000 275 Purchase returns and allowances 1,000 650 450 Cost of transportation-in 1,250 1,000 Merchandise inventory (beginning of period) 3,500 2,500 Net cost of merchandise purchases 43,700 19,250 Merchandise inventory (end of period) 1,700 3,250 Cost of goods sold $ 19,800 $ 16,065