the laurel corporation starts the year with a beginning inventory of 600 units at $5 per unit. the company purchases 1,000 units at $4 each in february and 400 units at $6 each in october. laurel sells 300 units during the year. laurel uses a periodic inventory system and the fifo inventory costing method. what is the amount of cost of goods sold? multiple choice $1,200 $1,868 $1,500 $1,800