(TCO 3) Kerner Manufacturing uses a process cost system to manufacture laptop computers. The following information summarizes operations relating to laptop computer model #KJK20 during the quarter ending March 31: Units Direct Labor Work-in-process inventory, January 1 200 $50,000 Started during the quarter 600 Completed during the quarter 500 Work-in-process inventory, March 31 300 Costs added during the quarter $720,000 Beginning work-in-process inventory was 50% complete for direct labor costs. Ending work-in-process inventory was 75% complete for direct labor costs. What is the equivalent amount of units of production using the weighted-average unit cost inventory valuation method?