The Repo Rock Company purchases rock by the ton to sell to construction companies. During the month of June, its first month of operations, Repo purchased the following: Repo Rock's only sale was on June 30. On June 30, the company sold 1, 370 tons of rock. Inventory at the end of June was 230 tons. Assuming the company uses a perpetual system, compute the cost of inventory at June 30 and the cost of goods sold for the month of June under each of the following cost flow assumptions: FIFO UFO Average cost method