please explain how to plug this question into excel.

Bama Tide Inc. typically uses equity as their main source of funding and typically only finances with 20% debt. The firm's after-tax cost of debt has been estimated to be 5% while their after-tax cost of equity is estimated at 8%. If the firm faces a 40% tax rate, what is their WACC? KAT=KBT(1T).WACC=wiki WACC \#1 \begin{tabular}{|c|c|} \hline State & Input \\ \hline Tax & \\ \hline Wd & \\ \hline Ws & \\ \hline Kd & \\ \hline Ks & \\ \hline Answer & \\ \hline \end{tabular}