1. (7 points) 1. Calculate: $\left(7 \frac{4}{25}+8.6\right) \div\left[\left(4 \frac{5}{7}-0.005 \times 900\right) \div \frac{6}{7}\right]=$
【Solution】Solve: $\left(7 \frac{4}{25}+8.6\right) \div\left[\left(4 \frac{5}{7}-0.005 \times 900\right) \div \frac{6}{7}\right]$
$$
\begin{array}{l}
=(7.16+8.6) \div\left[\left(4 \frac{5}{7}-4.5\right) \div \frac{6}{7}\right] \\
=15.76 \div\left[\frac{3}{14} \times \frac{7}{6}\right] \\
=15.76 \div \frac{1}{4} \\
=15.76 \times 4 \\
=63.04 .
\end{array}
$$

Therefore, the answer is: 63.04 .