During the month of June, Alfa company recorded the following: the beginning work in process balance for conversion costs was $1,900; $18,000 in conversion costs were incurred during the period; and the conversion costs for the units transferred out was $19,200. The beginning work-in-process inventory contained 400 physical units; 4,800 units were transferred out during the period. How many equivalent units for conversion costs were in the ending work in process inventory?