Independent solution

How to solve this Duration Immunization question

Setup

Setup

First value the fifteen-payment liability at 6.2% and compute its Macaulay duration from the discounted time-weighted cash flows.

PVL=35000a150.062=335530.30PV_L=35000a_{\overline{15}|\,0.062}=335530.30

Model

Model

Let X be the present-value amount in the five-year zero; the remainder of the liability present value goes into the ten-year zero. Equal duration gives a linear weighted-time equation.

DL=t=115t(35000)vtPVL=6.89214D_L=\frac{\sum_{t=1}^{15}t(35000)v^t}{PV_L}=6.89214

Compute

Compute

The liability value is 335,530.30 and its duration is 6.89214. Solving the duration equation gives X = 208,556, which rounds to 208,600.

5X+10(PVLX)=DLPVLX=2085565X+10(PV_L-X)=D_LPV_L\Longrightarrow X=208556

Answer

Answer

The calculation gives 208,600 for duration immunization, matching published choice C.

X=208600(C)\boxed{X=208600\quad\text{(C)}}