I am working on a problem that involves using FIFO, LIFO and average cost. I tried practicing the FIFO method and still get it wrong. the problem states: the following information pertains to Mason company for 2018

beginning inventory	120 units	$40
units purchased	330 units	$44

ending inventory consisted of 70 units. Mason sold 380 units at $88 each. All purchases and sales were made with cash. operating expenses amounted to $3100.