can someone help? and also tell me if im doing the second question correctly?

2. AT\&T has 7 percent coupon bonds on the market with 3 years left to maturity. The bonds make annual payments. If the bond currently sells for $900.00, what is its YTM? 3. A Taxable bond has a yield of 9% and a tax-free municipal bond has a yield of 6%. If you are in the 30% tax bracket, which bond would yield more on an after-tax basis? Show work: 9%(1T)9%(0.63)=