Pettis needs to determine its year-end inventory. the warehouse contains 20,000 units, of which 3,000 were damaged by flood and cannot be sold. another 2,000 units were purchased by pettis and shipped fob shipping point, and are in transit. the company also consigns goods and has 4,000 units at a consignee's location. how many units should pettis include in its year-end inventory?