The following information pertains to yap company's grinding department for the month of april: units materials costs beginning work in process 50,000 $13,200 started in april 96,000 $118,800 units completed and transferred out 112,500 ending work in process 33,500 all materials are added at the beginning of the process. using the weighted-average method, the cost per equivalent unit for materials is closest to: a) $1.02 b) $0.90 c) $1.17 d) $1.38