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)
	2020			2019			2018
Current assets	$	722		$	949		$	803
Other assets		2,420			1,927			1,726
Total assets	$	3,142		$	2,876		$	2,529
Current liabilities	$	584		$	837		$	730
Long-term liabilities		1,544			1,006			874
Stockholders equity		1,014			1,033			925
Total liabilities and stockholders' equity	$	3,142		$	2,876		$	2,529

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	$	3,057		$	2,920
Operating income		303			317
Interest expense		91			72
Net income		212			207
Other data:
Average number of common shares outstanding		42.0			47.4
Total dividends paid	$	57.0		$	53.0

Required:

1. Calculate return on investment, based on net income and average total assets, for 2020 and 2019.
2. Calculate return on equity for 2020 and 2019.
3. Calculate working capital and the current ratio for each of the past three years.
4. Calculate earnings per share for 2020 and 2019.
5. If Wiper's stock had a price/earnings ratio of 12 at the end of 2020, what was the market price of the stock?
6. Calculate the cash dividend per share for 2020 and the dividend yield based on the market price calculated in part e.
7. Calculate the dividend payout ratio for 2020.
8. Assume that accounts receivable at December 31, 2020, totaled $316 million. Calculate the number of days' sales in receivables at that date.
9. Calculate Wiper's debt ratio and debt/equity ratio at December 31, 2020 and 2019.
10. Calculate the times interest earned ratio for 2020 and 2019.