please help me answer this question. please give the most detail, full answer for section b). by using trend analysis. exhibit is in attached file.

Exhibit 4.21 presents selected operating data for three retailers for a recent year. Macy?s operates several department store chains selling consumer products such as brand-name clothing, china, cosmetics, and bedding and has a large presence in the bridal and formalwear markets (under store names Macy?s and Bloomingdale?s). Home Depot sells a wide range of building materials and home improvement products, which includes lumber and tools, riding lawn mowers, lighting fixtures, and kitchen cabinets and appliances. Supervalu operates grocery stores under numerous brands (including Albertsons, Cub Foods, Jewel-Osco, Shaw?s, and Star Market). a. Compute the rate of ROA for each firm. Disaggregate the rate of ROA into profit margin for ROA and assets turnover components. Assume that the income tax rate is 35 percent for all companies. b. Based on your knowledge of the three retail stores and their respective industry concentrations, describe the likely reasons for the differences in the profit margins for ROA and assets turnovers.