Cartwright Communications is considering making a change to its capital structure to reduce its cost of capital and increase firm value. Right now, Cartwright has a capital structure that consists of 20% debt and 80% equity, based on market values. The risk-free rate is 4% and the market risk premium is 5%. Currently the company's cost of equity, which is based on the CAPM, is 10% and its tax rate is 25%. What would be Cartwright's estimated cost of equity if it were to change its capital structure to 50% debt and 50% equity?