A 6.85 percent coupon bond with 26 years left to maturity is offered for sale at $1, XXXXXXXXXXWhat yield to maturity [interest rate] is the bond offering? Assume interest payments are paid...

A 6.85 percent coupon bond with 26 years left to maturity is offered for sale at $1,035.25. What yield to maturity [interest rate] is the bond offering? Assume interest payments are paid semi-annually, and solve using semi-annual compounding. I need this without the calculator! I can't even find the equation to do it by hand...