Swifty Corporation Inc. had a beginning inventory of $100$ units of Product RST at a cost of $$6$ per unit. During the year, purchases were:

Swifty Corporation uses a periodic inventory system. Sales totaled $1,550$ units.

$($a$)$

Determine the cost of goods available for sale.

The cost of goods available for sale

$($b$)$

Calculate average cost per unit

$($b$1)$

Determine the ending inventory and the cost of goods sold under each of the assumed cost flow methods $($FIFO$,$ LIFO, and average$-$cost$).$ Prove the accuracy of the cost of goods sold under the FIFO and LIFO methods.

$($c$)$

Which cash flow method results in the lowest inventory amount for the balance sheet? The lowest cost of goods sold for the income statement?