## Algebra and Trigonometry 10th Edition

$5.758$
We need to use an exponential decay model such as: $y= 6.5( \dfrac{1}{2})^{t/5715}$ The amount after $1000$ years is: $y= 6.5 \times ( \dfrac{1}{2})^{1000/5715} \approx 5.758$