A company has the following: December 1 Beginning inventory of 15 units at $6.00 per unit December 7 Purchased 60 units at $6.60 per unit December 12 Sold 40 units December 20 Purchased 30 units at $7.20 per unit December 29 Sold 20 units Assuming that a perpetual inventory system is used, what is the cost of goods sold on a LIFO basis for December? What if a periodic inventory system had been used instead of perpetual? $408 using perpetual, and $414 using periodic $414 using perpetual, and $408 using periodic $387 using perpetual, and $387 using periodic $409.50 using perpetual, and $423 using periodic $414 using perpetual, and $414 using periodic