A $10,000$ par value bond with $10\%$ semiannual coupons is callable at $9,250$ starting three years after its issue, at $9,600$ starting five years after its issue, and will mature at par after ten years. An investor purchased the bond assuming they will have a yield rate of at least $8\%$ convertible semiannually regardless of the call date. Eight years after issue, the borrower decided to call the bond. Use the bond salesman's formula to approximate the investor's actual yield rate $($convertible semiannually$)$ after the bond is called. When pricing the bond, assume that it can only be called on a coupon date.