Alyeska Services Company, a division of a major oil company, provides various services to the operators of the North Slope oil field in Alaska. Data concerning the most recent year appear below: Sales $ 7,500,000 Net operating income $ 600,000 Average operating assets $ 5,000,000 Required: Compute the margin. Compute the turnover. Note: Round your answer to 1 decimal place. Compute the return on investment (ROI). Note: Do not round intermediate calculations