CED a ITY A steel mill has the following income statement data: Units Sold Total Variable Costs Fixed Costs Total Costs Operating Total Revenue Income (Loss) 60,000 $ 120,000 $50,000 $170,000 $360,000 $190,000 80,000 160,000 50,000 210,000 480,000 270,000 a. Compute DOL based on the following formula: Percent change in operating income DOL Percent change in units sold b. Confirm that your answer to part a is correct by recomputing DOL using Formula 5-3. There may be a slight difference due to rounding, QP-VC) DOL Q(P-VC)-FC Qrepresents beginning units sold (all calculations should be done at this level). P can be found by dividing total revenue by units sold. VC can be found by dividing total variable costs by units sold