For this problem, an excel spreadsheet must be used to solve it. Thank you! 21. Southwestern Bell, a phone company, is considering ex- panding its operations into the media business. The beta for the company at the end of 1995 was 0.90, and the debt-to-equity ratio was 1. The media business is ex- pected to be 30% of the overall firm value in 1999, and the average beta of comparable firms is 1.20; the average debt-to-equity ratio for these firms is 50%. The marginal corporate tax rate is 36%. a. Estimate the beta for Southwestern Bell in 1999, assuming that it maintains its current debt-to-equity ratio. b. Estimate the beta for Southwestern Bell in 1999, assuming that it decides to finance its media operations with a debt-to-equity ratio of 50%.