PLEASE MAKE SURE THE ANSWER IS CORRECT!!!!!! NatNah, a builder of acoustic accessories, has no debt and an equity cost of capital of $\backslash (13\backslash \%\backslash ).$ Suppose NatNah decides to increas leverage to maintain a market debt$-$to$-$value ratio of $0\mathrm{.}4.$ Suppose its debt cost of capital is $\backslash (8\backslash \%\backslash )$ and its corporate tax rate is $\backslash (35\backslash \%\backslash ).$ If NatNah's pre$-$tax WACC remains constant, what will be its $($effective after$-$tax$)$ WACC with the increase in leverage?

The effective after$-$tax WACC will be

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