Ten years ago, Marky Inc's $7\mathrm{.}5\%$ bonds were issued with a maturity of $20$ years $($annual

coupons$).$ They are currently trading at $$1,013\mathrm{.}03.$ Marky intends to issue new annual coupon

bonds now with a maturity of ten years. When issued, these bonds will be set to trade at par.

What coupon rate must be set on these new bonds to make them trade at par? Show all work

including timelines, cashflows, equations, and all other work.