(1 point) (Exercise 6.15) You are given: (i) An n-year 4% semiannual coupon bond is purchased at a discount of X. (ii) An n-year 12.5% semiannual coupon bond is purchased at a premium of Y. (iii) An n-year 19% semiannual coupon bond is purchased at a premium of 2X. (iv) All bonds were purchased at the same yield rate and have the same par value. Calculate Y. Y =