Waterway Industries had 470 units of Dink in its inventory at a cost of $ 5 each. It purchased, for $ 2450, 310 more units of Dink. Waterway then sold 620 units at a selling price of $ 11 each, resulting in a gross profit of $ 2820. The cost flow assumption used by Waterway

is LIFO.

is FIFO.

is weighted average.

cannot be determined from the information given