Trying to answer the following request for a report on Walmart inc:

Taking the information from the Income statements and the Balance sheets, calculate the company's net profit margin, total assets turnover equity multiplier, and return on equity using the DuPont formula for the company for three years. Show your calculation

ROE = Net profit margin x Total assets turnover x Equity multiplier

= Net income/Sales x Sales/Total assets x Total assets/Common equity

You can use Revenue instead of Sales.

Compare the results to main competitor. For the major competitor you can use ratios from the Internet or calculate them for the last year.

please answer the question: If the management of the company would like to improve their return on equity, what should the management of these companies do?