$($Cost of equity$)$ The common stock for the Bestsold Corporation sells for $$58.$ If a new issue is sold, the flotation costs are estimated to be $8$ percent. The company pays $50$ percent of its earnings in dividends, and a $$4\mathrm{.}00$ dividend was recently paid. Earnings per share $5$ years ago were $$5\mathrm{.}00.$ Earnings are expected to continue to grow at the same annual rate in the future as during the past $5$ years. The firm's marginal tax rate is $34$ percent. Calculate the cost of $($a$)$ internal common equity and $($b$)$ external common equity.

a$.$ What is the firm's cost of internal common equity?

$\%($Round to two decimal places.$)$