XYZ Corp. has a debt$-$to$-$equity ratio of $0\mathrm{.}6,$ its equity cost of capital is $12\%,$ and it has risk$-$free

debt with an interest rate of $6\%.$ In perfect capital markets, what will be XYZ$\text{'}$s cost of equity

capital if it changes its debt$-$to$-$equity ratio to $0\mathrm{.}8?$