Flagstaff Enterprises expected to have free cash flow in the coming year of $$8$ million, and this free cash flow is expected to grow at a rate of $3\%$ per year thereafter. Flagstaff has an equity cost of capital of $13\%,$ a debt cost of capital of $7\%,$ and it has a $35\%$ corporate tax rate.

$1.$ If Flagstaff maintains a $\mathrm{.}5$ debt to equity ratio, calculate its pre$-$tax WACC

$2.$ If Flagstaff maintains a $\mathrm{.}5$ debt to equity ratio, calculate unlevered value of Flagstaff

$3.$ If Flagstaff maintains a $\mathrm{.}5$ debt to equity ratio, calculate its after$-$tax WACC

$4.$ If Flagstaff maintains a $\mathrm{.}5$ debt to equity ratio, calculate levered value of Flagstaff

$5.$ If Flagstaff maintains a $\mathrm{.}5$ debt to equity ratio, calculate value of Flagstaff's interest tax shield $($difference between Vl and Vu$)$