Booher Book Stores has a beta of $0\mathrm{.}5.$ The yield on a $3-$month T$-$bill is $5\%$ and the yield on a $10-$year T$-$bond is $6\%.$ The market risk premium is $7\mathrm{.}5\%,$ and the return on an average stock in the market last year was $13\%.$ What is the estimated cost of common equity using the CAPM? Round your answer to two decimal places.