Edisto Bank has an optimal capital structure that is $70\%$ common equity, $20\%$ debt, and $10\%$ preferred stock. The pretax cost of equity is $9\%,$ the pretax cost of preferred equity is $12\%,$ and the pretax cost of debt is $7\%.$ If the corporate tax rate is $30\%,$ what is the average cost of capital?

SHOW YOUR ANSWER AS A PERCENTAGE, ROUNDED TO $1$ DECIMAL PLACE $($DO NOT INCLUDE THE $\%$ SIGN$)$