Answer
Please see the work below.
Work Step by Step
We can find the worth of gold as
$8.0\times 10^4tons \space Au\times \frac{2000lb\space Au}{1\space ton Au}\times \frac{16ozAu}{1lb\space Au}\times \frac{$948}{1ozAu}=2.4\times 10^{22}$, or 2.4 trillion dollars