Situational Software Co$.($SSC$)$ is trying to establish its optimal capital structure. Its current capital structure consists of $35\%$ debt and $65\%$ equity; however, the CEO believes that the firm

should use more debt. The risk$-$free rate, $r_{RF},$ is $3\%$; the market risk premium, $R{P}_M,$ is $7\%$; and the firm's tax rate is $40\%.$ Currently, $SSC\text{'}$s cost of equity is $15\%,$ which is determined by the

CAPM.

What would be SSC$\text{'}$s estimated cost of equity if it changed its capital structure to $50\%$ debt and $50\%$ equity? Round your answer to two decimal places. Do not round intermediate steps.

$10$