The effect of tax rate on WACC$$K$.$ Bell Jewelers wishes to explore the effect on its cost of capital of the rate at which the company pays taxes. The firm wishes to maintain a capital structure of $35\%$debt$,10\%$ preferred$$ stock, and $55\%$ common stock. The cost of financing with retained earnings is $13\%,$ the cost of preferred stock financing is $9\%,$ and the$$ before$-$tax cost of debt financing is $8\%.$ Calculate the weighted average cost of capital $($WACC$)$ given a tax rate of $40\%.$