A six-year bond with par value of $4,000 has an annual coupon rate of 7%. It was purchased for $4,400 and may be called at m = 3, 4, 5, or 6. Its redemption value is $ 4,000. The call premiums are $250 in year 3, $240 in year 4, $230 in year 5 and $0 in year 6. [a] What is the yield to the investor in each case? [b] Calculate the call premium at each call date by using the constant yield rate 5.028% and varying the term of the bond.