Lucas Corporation uses the weighted-average method in its process costing system. Data concerning the first processing department for the most recent month are listed below: Beginning work in process inventory: Units in beginning work in process inventory 900 Materials costs $ 9,600 Conversion costs $ 7,700 Percent complete with respect to materials 60 % Percent complete with respect to conversion 45 % Units started into production during the month 8,100 Units transferred to the next department during the month 6,900 Materials costs added during the month $ 115,800 Conversion costs added during the month $ 120,500 Ending work in process inventory: Units in ending work in process inventory 2,100 Percent complete with respect to materials 75 % Percent complete with respect to conversion 20 % The cost per equivalent unit for conversion costs for the first department for the month is closest to. a. $13.570 b. $50.888c. S30,660d. $67.851