The future earnings, dividends, and common stock price of Callahan Technologies Inc. are expected to grow $7\%$ per year. Callahan's common stock currently sells for $$23\mathrm{.}75$ per share; its last dividend was $$2\mathrm{.}00$; and it will pay a $$2\mathrm{.}14$ dividend at the end of the current year.

a$.$ Using the DCF approach, what is its cost of common equity? Round your answer to two decimal places. Do not round your intermediate calculations. $\%$

b$.$ If the firm's beta is $2\mathrm{.}20,$ the risk$-$free rate is $5\%,$ and the average return on the market is $14\%,$ what will be the firm's cost of common equity using the CAPM approach? Round your answer to two decimal places. $\%$

c$.$ If the firm's bonds earn a return of $12\%,$ based on the bond$-$yield$-$plus$-$risk$-$premium approach, what will be $r_s?$ Use the midpoint of the risk premium range discussed in Section $10-5$ in your calculations. Round your answer to two decimal places.

$\%$

d$.$ If you have equal confidence in the inputs used for the three approaches, what is your estimate of Callahan's cost of common equity? Round your answer to two decimal places. Do not round your intermediate calculations.

$\%$