nordic industries uses a periodic inventory system. during its first month of operations, nordic industries purchased inventory as follows: units unit cost total cost january 3 150 $ 15 $ 2,250 january 12 200 20 4,000 january 20 250 20 5,000 january 25 300 30 9,000 900 $ 20,250 there were 100 units in ending inventory on january 31. under the lifo cost method, what is the cost of goods sold for january? multiple choice $17,250 $19,500 $18,750 $18,000