For fiscal year 2018 , Walmart Inc. (WMT) had total revenues of $500.34 billion, net income of $9.86 billion, total assets of $204.52 billion, and total shareholders' equity of $77.87 billion. a. Calculate Walmart's ROE directly, and using the DuPont Identity. b. Comparing with the data for Costco , use the DuPont Identity to understand the difference between the two firms' ROEs. Data table For fiscal year 2018, Costco Wholesale Corporation (COST) had a net profit margin of 2.08\%, asset turnover of 3.55 , and a book equity multiplier of 3.37 . Costco's ROE (DuPont) is 24.88%