Exercise $6-14$A $($Algo$)$ Periodic: Cost flow assumptions LO P$3$

Lopez Company reported the following current$-$year data for its only product. The company uses a periodic inventory system, and its

ending inventory consists of $540$ units$-180$ from each of the last three purchases.

$($a$-$d$)$ Determine the cost assigned to ending inventory and to cost of goods sold for the following.

$($e$)$ Which method yields the highest net income?