Presented here are summarized data from the balance sheets and income statements of Wiper Inc.: WIPER INC. Condensed Balance Sheets December 31, 2020, 2019, 2018 (in millions) Current assets Other assets Total assets Current liabilities Long-term liabilities Stockholders' equity Total liabilities and stockholders' equity 2020 $ 829 2,433 $3,262 $ 597 1,638 1,027 $3,262 2019 $1,071 1,940 $3,011 $ 850 1,115 1,046 $3,011 2018 $ 933 1,739 $2,672 $ 752 982 938 $2,672 WIPER INC. Selected Income Statement and Other Data For the year Ended December 31, 2020 and 2019 (in millions) 2020 2019 Income statement data: Sales Operating income Interest expense Net income Other data: Average number of common shares outstanding Total dividends paid $3,070 316 104 251 $2,933 330 85 246 43.3 $ 70.0 48.7 $ 54.3 Required: a. Calculate return on investment, based on net income and average total assets, for 2020 and 2019. b. Calculate return on equity for 2020 and 2019. c. Calculate working capital and the current ratio for each of the past three years. d. Calculate earnings per share for 2020 and 2019. e. If Wiper's stock had a price/earnings ratio of 12 at the end of 2020, what was the market price of the stock? f. Calculate the cash dividend per share for 2020 and the dividend yield based on the market price calculated in parte g. Calculate the dividend payout ratio for 2020. h. Assume that accounts receivable at December 31, 2020, totaled $329 million. Calculate the number of days' sales in receivables at that date. i. Calculate Wiper's debt ratio and debt/equity ratio at December 31, 2020 and 2019. j. Calculate the times interest earned ratio for 2020 and 2019