DDD is an unlevered firm with a cost of capital of $17\mathrm{.}4\%.$ The company is considering adding debt to its capital structure to reduce equity. Specifically, the company is evaluating the consequences of adding $$4$ million in perpetual debt at a pre$-$tax cost of $6\mathrm{.}3\%.$ The firm expects to generate EBIT of $$7$ million every year into perpetuity. Assume interest expense is tax deductible. The firm pays a tax rate of $31\%.$ Ignore financial distress costs.

Based on MM Prop II$,$ what will be DDD$\text{'}$s weighted average cost of capital if it takes on the debt? PROVIDE THE SOLUTION TO THE WACC, I know what the formula is$...$