\({{1 \over 2} \over {3 \over 4}}={0.5 \over 0.75}={0.5 \cdot 100 \over 0.75 \cdot 100}={50 \over 75}={50 \div 25 \over 75 \div 25}={2 \over 3}=0.\overline{66}\)