The McGee Corporation finds it is necessary to determine its marginal cost of capital. McGee$$s current capital structure calls for $50$ percent debt, $25$ percent preferred stock, and $25$ percent common equity. Initially, common equity will be in the form of retained earnings $($Ke$)$ and then new common stock $($Kn$).$ The costs of the various sources of financing are as follows: debt $($after$-$tax$),7\mathrm{.}2$ percent; preferred stock, $10\mathrm{.}0$ percent; retained earnings, $12\mathrm{.}0$ percent; and new common stock, $13\mathrm{.}2$ percent.

What is the initial weighted average cost of capital? $($Include debt, preferred stock, and common equity in the form of retained earnings, Ke $.)$

Note: Do not round intermediate calculations. Input your answers as a percent rounded to $2$ decimal places.

If the firm has $$18\mathrm{.}5$ million in retained earnings, at what size capital structure will the firm run out of retained earnings?

Note: Enter your answer in millions of dollars $($e$.$g$.,$ $$10$ million should be entered as $"10").$

What will the marginal cost of capital be immediately after that point? $($Equity will remain at $25$ percent of the capital structure, but will all be in the form of new common stock, Kn $.)$

Note: Do not round intermediate calculations. Input your answer as a percent rounded to $2$ decimal places.

The $7\mathrm{.}2$ percent cost of debt referred to above applies only to the first $$50$ million of debt. After that, the cost of debt will be $9\mathrm{.}2$ percent. At what size capital structure will there be a change in the cost of debt?

Note: Enter your answer in millions of dollars $($e$.$g$.,$ $$10$ million should be entered as $"10").$

What will the marginal cost of capital be immediately after that point? $($Consider the facts in both parts c and d$.)$

Do not round intermediate calculations. Input your answer as a percent rounded to $2$ decimal places.