\[\frac{45^{4}}{75^{3}} = \frac{5^{4} \cdot \left( 3^{2} \right)^{4}}{\left( 5^{2} \right)^{3} \cdot 3^{3}} = \frac{5^{4} \cdot 3^{8}}{5^{6} \cdot 3^{3}} =\]
\[= \frac{3^{5}}{5^{2}} = \frac{243}{25} = 9\frac{18}{25} = 9,72\]