The Black Hills Corporation issued a new series of bonds on January 1, 1990. The bonds were sold at par ($1,000), had a 12% coupon, and matured in 30 years on December 31, 2019. Coupon payments are made semiannually. 

a. What was the YTM on the date the bonds were issued?

b. What was the price of the bonds on January 1, 1995, assuming that interest rates had fallen to 10%.

c. Find the current yield, capital gains yield, and total yield on January 1, 1995, given the price as determined in part b.

d. On July 1, 2013 lack Hills’ bonds sold for $916.42. What are the YTM, the current yield, and the capital gains yield for that date?