P1-41. Computing Return on Equity and Return on Assets The following table contains financial statement information for Walmart Inc. $ millions 2018... 2017. 2016. Required Total Assets Net Income Sales Equity $219,295 $ 6,670 $510,329 $72,496 204,522 198,825 9,862 495,761 77,869 13,643 481,317 77,798 a. Compute return on equity (ROE) for the two recent years. b. Compute return on assets (ROA) for the two recent years. c. Compute profit margin (PM) for the two recent years. d. Compute asset turnover (AT) for the two recent years. e. Which of the following best explains the change in ROA during 2018? 1. The company's profitability weakened considerably. 2. The company's asset productivity weakened considerably. 3. The company had higher sales in 2018. 4. The company had higher assets 2018.