Rhiannon Corporation has bonds on the market with $13$ years to maturity, a YTM of $7\mathrm{.}6\%,$ a

par value of $$1,000,$ a current market price of $$1,075.$ The bonds make semiannual payments.

a$.$ What must the coupon rate be on these bonds?

b$.$ What would be coupon rate if the current market price is $$962\mathrm{.}68?$

c$.$ What would be the coupon rate if the bonds make quarterly payments