(Bond valuation relationships) A bond of Visador Corporation pays $80 in annual interest, with a $1,000 par value. The bonds mature in 21 years. The market's required yield to maturity on a comparable-risk bond is 7.5 percent. a. Calculate the value of the bond. b. How does the value change if the market's required yield to maturity on a comparable-risk bond (i) increases to 13 percent or (ii) decreases to 5 percent? c. Interpret your finding in parts a and b