Elliot Karlin is a 35-year-old bank executive who has just inherited a large sum of money. Having spent several years in the bank's investments department, he's well aware of the concept of duration and decides to apply it to his bond portfolio. In particular, Elliot intends to use $1 million of his inheritance to purchase four U.S. Treasury bonds: 1. An 8.66%, 13-year bond that's priced at $1,097.03 to yield 7.48%. 2. A 7.815%, 15-year bond that's priced at $1022.65 to yield 7.56%. 3. A 20-year stripped Treasury (zero coupon) that's priced at $197.38 to yield 8.28%. 4. A 24-year, 7.45% bond that's priced at $956.04 to yield 7.86%. Note that these bonds are semiannual compounding bonds. a. Find the duration and the modified duration of each bond. b. Find the duration of the whole bond portfolio if Elliot puts $250,000 into each of the four U.S. Treasury bonds. c. Find the duration of the portfolio if Elliot puts $340,000 each into bonds 1 and 3 and $160,000 each into bonds 2 and 4. d. Which portfoliob or cshould Elliot select if he thinks rates are about to head up and he wants to avoid as much price volatility as possible? Explain. From which portfolio does he stand to make more in annual interest income? Which portfolio would you recommend, and why?

a. The duration and modified duration can be calculated using a spreadsheet, such as Excel. It gives the precise duration measure because it avoids the rounding-off errors, which are inevitable with manual calculations.

Bond 1: 13 years,8.66%,priced to yield 7.48%.

The duration of this bond is ___years.

b. Find the duration of the whole bond portfolio if Elliot puts $250,000 into each of the 4 U.S. Treasury bonds.When Elliot invests$250,000 in each of the four bonds, the weighted average duration of the portfolio is:

c. Find the duration of the portfolio if Elliot puts $350,000 each into bonds 1 and 3 andn$150,000 each into bonds 2 and 4. When Elliot invests$350,000 each into bonds 1 and 3, and $150,000 each into bonds 2 and 4, the weighted average duration of the bond portfolio is: