Comparing Bell and Gangway. Financial information for Bell and Gangway (two computer manufacturers) follows:

	BELL	GANGWAY
(in millions)	Year Ended 12/31/2020	Year Ended 12/31/2019	Year Ended 12/31/2020	Year Ended 12/31/2019
Sales	$61,133	$57,420	$8,922	$8,457
Cost of sales	$49,462	$47,904	$7,316	$6,951
Gross Margin	$11,671	$9,516	$1,606	$1,506
Inventory	$1,180	$660	$400	$351

Required:

a. Compared Bell and Gangway in terms of their percentage changes in sales and gross margin (explain with calculations)

b. Compared Bell and Gangway in terms of their gross margin percentages (explain with calculations)

c. Compared Bell and Gangway in terms of Inventory turnover and days' sales in inventory (explain with calculations)

d. In detail, which firm has had better financial performance? Support the answer using your calculations in parts a, b and c.