Please explain how to solve the problem, don't just give the answer with no explanation.

Required information Problem 7-9A Calculate and interpret ratios (LO7-7) [The following information applies to the questions displayed below.] Sub Station and Planet Sub reported the following selected financial data ($ in thousands). Sub Station's business strategy is to sell the best tasting sandwich with the highest quality ingredients. Planet Sub's business strategy is to sell the lowest cost sub on the planet. Net sales Net income Total assets, beginning Total assets, ending Sub Station $109, 949 27,622 76,883 119,771 Planet Sub $63,771 5,192 41,799 47,933 Problem 7-9A Part 1 Required: 1. Calculate Sub Station's return on assets, profit margin, and asset turnover ratio. (Enter your answers in thousands of dollars. (i.e. 123,000 should be entered as 123).) Return on Assets Choose Denominator Choose Numerator : Return on Assets Return on assets Profit Margin Choose Denominator Choose Numerator : = Profit Margin Profit Margin = Asset Turnover Choose Denominator Choose Numerator : = Asset Turnover = Asset Turnover times