12. Upson, which started in 2019, purchases inventory quarterly and uses LIFO costing under the periodic method. Its 20192021inventory records are:

Purchase date	Units	Unit cost	Total cost
2019
January	2,600	$17	$44,200
April	700	$16	11,200
July	3,300	$19	62,700
October	1,300	$22	28,600
Ending inventory	900
2020
January	1,300	$22	$28,600
April	1,500	$23	34,500
July	1,000	$24	24,000
October	2,000	$25	50,000
Ending inventory	1,400
2021
January	1,000	$25	$25,000
April	1,300	$25	32,500
July	1,300	$26	33,800
October	1,800	$27	48,600
Ending inventory	1,700

Calculate CoGS and EI for 2020. Provide calculations in an easy-to-follow schedule.