[The following information applies to the questions displayed below.] Blackwood Industries manufactures die machinery. To meet its expansion needs, it recently (2020) acquired one of its suppliers, Delta Steel. To maintain Delta's separate identity, Blackwood reports Delta's operations as an investment center. Blackwood monitors all of its investment centers on the basis of return on investment (ROI). Management bonuses are based on ROI, and all investment centers are expected to earn a minimum 10% return before income taxes. Delta's ROI has ranged from 14% to 18% since 2020. The company recently had the opportunity for a new investment that would have yielded a 13% ROI. However, division management decided against the investment because it believed that the investment would decrease the division's overall ROI. The 2022 operating statement for Delta follows. The division's operating assets were $38,400,000 at the end of 2022, a 1% increase over the 2021 year-end balance. Sales DELTA DIVISION Operating Statement For Year Ended December 31, 2022 (000s omitted) Cost of goods sold Gross profit Operating expenses: Administration Selling Operating income $ 113,500 73,775 39,725 $ 16,808 16,932 33,740 $ 5,985 Required: 1. Calculate the following performance measures for 2022 for the Delta division: a. Return on average investment in operating assets. (Round your final answer to 2 decimal places.) b. Residual income (RI) calculated on the basis of average operating assets. (Enter your answer in whole dollars.) 1a. Return on investment 1b. Residual income 15.69 %