Please solve the problems by calculator and show your work

11. Blue Sky Townhomes has 8% bonds outstanding that mature in 13 years. The bonds pay interest semiannually. These is equal price bonds have a par value of si and are callable S75. What is the yield to call if the current to 103.25% of par? 12. A yielding 5% while a municipal bond of similar credit quality (both are ranked as Moody's Baa bonds) is corporate bond is yielding 3%. Above what tax rate are investors selecting the municipal bond for their portfolios? 13. An investor's tax bracket is 35%. If municipal bonds with the same level as corporate bonds are yielding 4%, what is of risk the corporate yield