Concord Company decided to analyze certain costs for June of the current year. Units started into production equaled $28000$ and ending work in process inventory equaled $3000.$ If there was no beginning work in process inventory, what is the conversion cost per unit if ending work in process inventory was $20\%$ complete as to conversion costs and total conversion costs equaled $$140800?$

$$5\mathrm{.}50.$

$$5\mathrm{.}63.$

$$4\mathrm{.}54.$

$$5\mathrm{.}03$