Consider the following financial data for Walmart Inc. and Amazon.com Inc. for the fiscal year 2023:

($ millions)	Walmart Inc.	Amazon.com Inc.
Net sales	$572,754	$469,822
Cost of sales	433,891	370,532
Gross profit	138,863	99,290
Operating expenses:
Selling, general, and administrative	105,360	88,472
Operating income	33,503	10,818
Interest and other (income) expense	4,345	2,604
Interest and investment income	(1,207)	(916)
Earnings before provision for income taxes	30,365	9,130
Provision for income taxes	7,591	2,562
Net earnings	$22,774	$6,568

Required: a. Calculate the return on equity (ROE), return on assets (ROA), and return on financial leverage (ROFL) for Walmart Inc. and Amazon.com Inc. Assume a tax rate of 30%. b. Disaggregate the ROA into profit margin (PM) and asset turnover (AT) for each company. Discuss the key factors affecting their ROA. c. Evaluate the trend in gross profit margins over the past five years. What does this trend indicate about the companies' operational efficiency? d. Assess the debt-to-equity ratio for both companies and discuss the implications for their financial leverage. e. Analyze the free cash flow for Walmart Inc. and Amazon.com Inc. What does it indicate about their liquidity and ability to fund growth?