Question 8 colby company has a process costing system in which the weighted-average method is used. the company adds all materials at the beginning of the process in the molding department, which is the first of two stages of its production process. information concerning the materials used in the molding department during march is as follows: work in process at march 1: units = 22,000; material costs = $11,000units started during march: units = 90,000; materials costs = $46,120units completed and transferred to the next department during march: units = 97,000what was the materials cost of the work in process inventory at march 31? (a) $11,220(b) $7,500(c) $5,100(d) $7,650