Physical Units Direct Conversion (ball bearings) Materials Costs Work-in-process, September 1 400 $76,800 $12,240 Started during September 2018 2,800 Good units completed and transferred out during September 2018 1,400 Work-in-process, September 30b 300 Costs added during September 2018 $453,600 $184,320 * Degree of completion: direct materials, 100%; conversion costs, 30%. Degree of completion: direct materials, 100%; conversion costs, 40%.