1. Calculate $\frac{2}{1} \times \frac{2}{3} \times \frac{4}{3} \times \frac{4}{5} \times \frac{6}{5} \times \frac{6}{7} \times \frac{8}{7}=$ $\qquad$.(Write in decimal form, accurate to two decimal places.)
Analysis:
After simplification, it becomes: $\frac{2^{11}}{5^{2} \times 7^{2}}=2^{11} \div\left(5^{2} \times 7^{2}\right)=1.67183 \ldots \ldots$. After rounding to two decimal places, the answer is 1.67.