Below is the financial information for Exxon Mobil Corporation and Chevron Corporation for the fiscal year 2023:

($ millions)	Exxon Mobil Corporation	Chevron Corporation
Net sales	$398,674	$261,162
Cost of sales	243,987	157,886
Gross profit	154,687	103,276
Operating expenses:
Selling, general, and administrative	48,789	34,879
Research and development	4,872	3,481
Operating income	101,026	64,916
Interest and other (income) expense	9,247	6,743
Interest and investment income	(2,310)	(1,976)
Earnings before provision for income taxes	94,089	60,149
Provision for income taxes	20,699	13,834
Net earnings	$73,390	$46,315

Required: a. Calculate the return on equity (ROE), return on assets (ROA), and return on financial leverage (ROFL) for Exxon Mobil Corporation and Chevron Corporation. Assume a tax rate of 25%. b. Disaggregate the ROA into profit margin (PM) and asset turnover (AT) for both companies. Discuss the key factors affecting their ROA. c. Analyze the trend in research and development (R&D) expenses over the past five years. How does it impact their innovation and long-term growth? d. Evaluate the current ratio and quick ratio for Exxon Mobil Corporation and Chevron Corporation. What does it reveal about their short-term liquidity? e. Compare the interest coverage ratios for Exxon Mobil Corporation and Chevron Corporation. What insights can be drawn about their financial stability and ability to meet interest obligations?