department. Process Costing and a Work in Process Inventory Accourt SE3. Pro Chemicals uses an automated mixing machine in its Mixing Department to combine three raw materials into a product called Trio. On average, each unit of Trio contains $3 of Material X, S6 of Material Y, $9 of Material Z, $2 of direct labor, and $10 of overhead. Total costs charged to the Mixing Department's Work in Process Inventory account during the month were $210,000. There were no units in beginning or ending work in process inventory. How many units were completed and transferred to finished goods inventory during the month