Laker Company reported the following January purchases and sales data for its only product. For specific identification, ending inventory consists of $270$ units from the January $30$ purchase, $5$ units from the January $20$ purchase, and $15$ units from beginning inventory.

The Company uses a periodic inventory system. For specific identification, ending inventory consists of $270$ units from the January $30$ purchase, $5$ units from the January $20$ purchase, and $15$ units from beginning inventory. Determine the cost assigned to ending inventory and to cost of goods sold using $($a$)$ specific identification, $($b$)$ weighted average, $($c$)$ FIFO, and $($c$)$ LIFO.