Bistrol Corporation uses the weighted$-$average method in its process costing system. This month, the beginning inventory in the first processing department consisted of $800$ units. The costs and percentage completion of these units in beginning inventory were:

Cost Percent Complete

Materials costs $ $15,70075\%$

Conversion costs $ $7,70020\%$

A total of $8,400$ units were started and $7,500$ units were transferred to the second processing department during the month. The following costs were incurred in the first processing department during the month:

Cost

Materials costs $ $186,300$

Conversion costs $ $329,800$

The ending inventory was $70\%$ complete with respect to materials and $60\%$ complete with respect to conversion costs.

The cost per equivalent unit for conversion costs for the first department for the month is closest to: