please show complete work. Thank you.

3) Consider a $1000 par value 5% bond with semiannual coupons callable at $$1100 any coupon date starting 2 years after issue for the next 2 years, at $1050 starting 4 years after issue for the next 2 years, and maturing at $1000 at the end of 6 years. Find the highest price which an investor can pay and still be certain of a yield of a) 4% convertible semiannually b) 8% convertible semiannually