Galaxy Manufacturing uses a process$-$costing system. Galaxy uses the weighted average method. The following information pertains to operations for the month of January:

Line Item DescriptionUnitsBeginning work$-$in$-$process inventory, January $114,000$Started in production during January$370,000$Completed production during January$187,000$Ending work$-$in$-$process inventory, January $31177,000$

The beginning inventory was $80\%$ complete for materials and $40\%$ complete for conversion costs. The ending inventory was $85\%$ complete for materials and $30\%$ complete for conversion costs.

Costs pertaining to the month of January are as follows:

Beginning inventory costs: materials $=$ $$152,800$; conversion cost $=$ $$165,600$

Costs incurred during January: materials used $=$ $$1,849,200$; conversion cost $=$ $$2,410,800$

Calculate the unit cost of materials for January. $($Round answer to two decimal places.$)$

a$.$ $$10\mathrm{.}45$

b$.$ $$5\mathrm{.}65$

c$.$ $$9\mathrm{.}80$

d$.$ $$5\mathrm{.}22$