Rewrite both fractions so they have a common denominator, 16. You find that $\displaystyle\frac{{8}}{{16}}<\frac{{9}}{{16}}\usepackage{cmbright}\Huge\$ , so $\displaystyle\frac{{4}}{{8}}<\frac{{9}}{{16}}\usepackage{cmbright}\Huge\$ as well.