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 moulding department, which is the first of two stages of its production process. Information concerning the materials used in the moulding department during March is as follows: Materials Units costsWork in progress at March 1 22,000 € 15,480Units started during March 90,000 € 46,120Units completed and transferred tonext department during March 100,000 What was the materials cost of the work-in-progress inventory at March 31?