You are given the following information

Bond A has a price of $ 123.78, it matures on Jan-2030, its coupon rate is 3.78%, and it's AAA-rated

Bond B has a price of $ 117.34, it matures on Jan-2030, its coupon rate is3.65%and it's AA-rated

Bond C has a price of $ 119.22, it matures on Jan-2030, its coupon rate is 3.96%, and it's BBB-rated.

Bond D has a price of $ 129.3, it matures on Jan-2030, its coupon rate is 7.2%, and it's BB-rated.

US Bond X has a price of $ 110.25, it matures on June-2029, and its coupon rate is 1.78%

US Bond Y has a price of $ 111.27, it matures on July-2030, and its coupon rate is1.95%

a) Calculate the credit risk premium of each of the given rated bonds.

b)Let's say that you have to price a 10-year AAA-rated bond that is issued on Nov 30, 2020 Calculate the coupon for the bond if you are given that the risk-free rate on that day will be 0.69% and that the credit premiums remained the same.

Note: all coupon rates are per annum with semi-annual compounding