6. State why you would agree or disagree with the following statement: When interest rates are low, there will be little difference between the Macaulay duration and modified duration measures. 14. Answer the below questions. (a) Suppose that the spread duration for a fixed-rate bond is 2.5. What is the approximate change in the bond's price if the spread changes by 50 basis points? (b) What is the spread duration of a Treasury security? 17. Consider the following portfolio: (a) What is the portfolio's duration? (b) If interest rates for all maturities change by 50 basis points, what is the approximate percentage change in the value of the portfolio? (c) What is the contribution to portfolio duration for each bond? 6. State why you would agree or disagree with the following statement: When interest rates are low, there will be little difference between the Macaulay duration and modified duration measures. 14. Answer the below questions. (a) Suppose that the spread duration for a fixed-rate bond is 2.5. What is the approximate change in the bond's price if the spread changes by 50 basis points? (b) What is the spread duration of a Treasury security? 17. Consider the following portfolio: (a) What is the portfolio's duration? (b) If interest rates for all maturities change by 50 basis points, what is the approximate percentage change in the value of the portfolio? (c) What is the contribution to portfolio duration for each bond