While calculating the 'Cost per Equivalent Units of Production (EUP)' in this example, is it appropriate to use the first in, first out (FIFO) method? Or should I instead calculate 'Cost per EUP' with the 'Cost of beginning work-in-process (WIP)' included?

Problem Information Intense Co. manufactures a product that uses two production departments. Units are begun in the Mixing Department and then transferred to the Finishing Department. O O Below is information related to Intense Co.'s Mixing Department during the current period: The Mixing Department began the period with 50,000 units of beginning inventory, costing $225,000. The $225,000 consisted of $90,000 of materials cost and $135,000 of conversion costs. The units in beginning inventory were 40% complete with regard to materials and 50% complete with regard to conversion costs. During the period an additional 300,000 units were started in the Mixing Department. Costs added to production during the period consisted of $785,000 of materials and $560,000 of conversion costs. As of the end of the period, 11,180 units were still unfinished and in work in process. The units were 70% complete with regard to materials and 20% complete with regard to conversion costs