Your firm plans to offer new 15-year bonds to replace their existing issue that also has 15 years to maturity. The existing bonds have a $1,000 par value, a 6.5% semi-annual coupon, and are priced at $1,280. If you would like the new bonds to sell at par, and assuming the required return on the new bonds will be the same as the existing issue, what coupon rate should the new bonds have