Current Attempt in Progress

You are analyzing the after$-$tax cost of debt for a firm. You know that the firm's $12-$year maturity, $18\mathrm{.}00$ percent semiannual coupon bonds are selling' at a price of $$1,552.$ Assuming that these bonds are the only debt outstanding for the firm.

Problem $13\mathrm{.}19$ a$1-$a$3($a$1)$

What is the current YTM of the bonds? $($Round intermediate calculations to $4$ decimal places, e$.$g$.1\mathrm{.}2514$ and final answer to $2$ decimal places, e$.$g$.15\mathrm{.}25\%.)$

YTM $\%$