$1.$ The Denver Company currently has a bond issue outstanding which carries a coupon rate of $6\mathrm{.}4$ percent, makes semiannual payments, currently sells for $$967\mathrm{.}40,$ and matures in $8\mathrm{.}4$ years. Suppose Denver Company wants to issue another bond issue which will mature in $25$ years to expand its current operations. Assuming this new bond issue is similar in risk to the existing bonds outstanding, what coupon rate should Denver set on these new bonds if it wants them to sell at par?