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Selected comparative statement data for Willow Products Company are presented below. All balance sheet data are as of December 31. 2019 2018 Net sales P800,000 P720,000 Cost of goods sold 480,000 440,000 Interest expense 7,000 5,000 Net income 60,000 42,000 Accounts receivable 120,000 100,000 Inventory 85,000 75,000 Total assets 600,000 500,000 Total common stockholders' equity 430,000 320,000 Compute the following ratios for 2019: (a) Profit margin. (b) Asset turnover. (c) Return on assets. (d) Return on common stockholders' equity