Independent solution

How to solve this Interest Rate Measures question

Setup

Setup

A time-varying force accumulates one unit by the exponential of its integral.

AX(20)=exp(02021+2tdt)A_X(20)=\exp\left(\int_0^{20}\frac{2}{1+2t}\,dt\right)

Model

Model

The integral is the logarithm of 1 + 2t evaluated from 0 to 20.

AX(20)=eln41=41=(1+i)20A_X(20)=e^{\ln41}=41=(1+i)^{20}

Compute

Compute

Five years is one quarter of the common 20-year horizon, so Fund Y's value is 2.530440.

AY(5)=411/4=2.53043953A_Y(5)=41^{1/4}=2.53043953

Answer

Answer

Fund Y is worth approximately 2.53 after five years, selecting choice B.

AY(5)2.53(B)\boxed{A_Y(5)\approx2.53\quad\text{(B)}}