Periodic Inventory by Three Methods

The units of an item available for sale during the year were as follows:

Jan. $1$ Inventory $11$ units at $$41$

Feb. $17$ Purchase $12$ units at $$42$

Jul. $21$ Purchase $8$ units at $$45$

Nov. $23$ Purchase $15$ units at $$47$

a$.$ Determine the inventory cost by the first$-$in$,$ first$-$out method.

$

b$.$ Determine the inventory cost by the last$-$in$,$ first$-$out method.

$

$