Titan Mining Corporation has $6\mathrm{.}4$ million shares of common stock outstanding and $175,000($units of$)6$ percent semiannual bonds outstanding, par value $$1,000$ each. $($Hint: the coupon payment every $6$ months is $$30.)$ The common stock currently sells for $$53$ per share and has a beta of $1\mathrm{.}15$; the bonds have $5$ years to maturity and sell for $$1,060$ per unit. The market risk premium is $6\mathrm{.}8$ percent, T$-$bills are yielding $3\mathrm{.}1$ percent, and the company's tax rate is $21$ percent.$$

b$.$ What is the cost of debt for the company?