Calculating WACC $[$ LO$1]$ Navarro Corp. has no debt but can borrow at $5\mathrm{.}9$ percent. The firm's WACC is currently $9\mathrm{.}2$ percent, and the tax rate is $21$ percent.

a$.$ What is the company's cost of equity?

b$.$ If the firm converts to $25$ percent debt, what will its cost of equity be$?$

c$.$ If the firm converts to $50$ percent debt, what will its cost of equity be$?$

d$.$ What is the company's WACC in part $($b$)?$ In part $($c$)?$

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