The difference in the Assembly Department cost per unit calculated in requirements 1 and
2 arises because the costs incurred in January and February are the same but fewer equivalent
units of work are done in February relative to January. In January, all 10,000 units introduced are
fully completed resulting in 10,000 equivalent units of work done with respect to direct materials
and conversion costs. In February, of the 10,000 units introduced, 10,000 equivalent units of
work is done with respect to direct materials but only 9,500 equivalent units of work is done with
respect to conversion costs. The Assembly Department cost per unit is, therefore, higher.