The debits to Work in Process--Assembly Department for April, together with data concerning production, are as follows: April 1, work in process: Materials cost, 3,000 units $ 8,000 Conversion costs, 3,000 units, 66.7% completed 6,000 Materials added during April, 10,000 units 30,000 Conversion costs during April 31,000 Goods finished during April, 11,500 units --- April 30 work in process, 1,500 units, 50% completed --- All direct materials are placed in process at the beginning of the process and the first-in, first-out method is used to cost inventories. The materials cost per equivalent unit for April is: $3.00 $3.80 $2.92 $2.31