. Problem 4 (Required, 25 marks) We consider a 20-year callable bond issued today. The bond has face value F = 1000, annual coupon rate 6% payable semi-annually. The bond is callable at any coupon payment date starting from gth year. The redemption price is $1300 if the bond is called in gth-13th year and is $1150 if the bond is called in 14th year-20th year (including maturity date). The minimum yield rate of the callable bond, quoted as annual nominal yield rate, is 4.8%. Question: (a) Calculate the current price of the callable bond. (b) Hence, calculate the maximum annual nominal yield rate of the callable bond. (Hint: It appears that the theorems in the lecture note do not work. Is it possible for us to modify it? Please show details.)