A firm has a cost of debt of $6$ percent and a cost of equity of $10\mathrm{.}9$ percent. The debt$$equity ratio is $\mathrm{.}60.$ There are no taxes. What is the firm's weighted average cost of capital?

Group of answer choices

$9\mathrm{.}54\%$

$8\mathrm{.}16\%$

$7\mathrm{.}55\%$

$9\mathrm{.}06\%$