Epson has one bond outstanding with a yield to maturity of $7\%$ and a coupon rate of $8\%.$ The company has no preferred stock. Epson's beta is $1\mathrm{.}1,$ the risk$-$free rate is $2\mathrm{.}8\%$ and the expected market risk premium is $6\%.$

Epson has a target debt$/$equity ratio of $0\mathrm{.}8$ and a marginal tax rate of $34\%.$ a$.$ What is Epson's $($pre$-$tax$)$ cost of debt? b$.$ What is Epson's cost of equity? c$.$ What is Epson's capital structure weight for equity, i$.$e$.,$ the fraction of long$-$term capital provided by equity? d$.$ what is their WACC?