a$.$ Calculate the cost of each capital component, that is$,$ the after$-$tax cost of debt, the cost of preferred stock $($including flotation costs$),$ and the cost of equity $($ignoring flotation costs$).$ Use both the the CAPM method and the dividend growth approach to find the cost of equity.

Cost of debt:

Cost of common equity, dividend growth approach $($ignoring flotation costs$)$: