Duration = (52/153) × 8.2 + (61/153) × 6.8 + (40/153) × 5 = 6.8
Entering this into the following formula gives us the change in value of the portfolio:
Change in value of the portfolio = (market value) × (duration) × (expected change in yield)
Change in value of the portfolio = $153,000 × 6.8 × 0.0025 = $2,601
