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 $360$ units $\backslash (-120\backslash )$ 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. $($Do not round intermediate calculations and round your answers to $2$ decimal places.$)($e$)$ Which method yields the highest net income?