b$.$ Determine the inventory cost by the last$-$in$,$ first$-$out method. The units of an item available for sale during the year were as follows:

Date Line Item Description Value

Jan. $1$ Inventory $2,500$ units at $$4$

Feb. $17$ Purchase $2,800$ units at $$5$

Jul. $21$ Purchase $3,000$ units at $$6$

Nov. $23$ Purchase $1,700$ units at $$7$