Please provide an explanation or cite sources of info.

The following transactions occurred during the month of January for the Joplin Company: 1/1 1/6 1/9 1/16 1/20 1/28 Beginning inventory consists of 50 units @ $30 Sold 40 units @ $50 Purchased 100 units @ $32 Sold 80 units @ $52 Purchased 110 units @ $33 Sold 60 units @ $54 (A) Compute cost of goods sold for January assuming the weighted average method is used: (B) Compute cost of goods sold for January assuming a FIFO inventory method is used: $ (C) Compute cost of goods sold for January assuming a LIFO inventory method is used: $