Rewrite both fractions so they have a common denominator, 8. You find that $\displaystyle\frac{{3}}{{8}}<\frac{{4}}{{8}}\usepackage{cmbright}\Huge\$ , so $\displaystyle\frac{{3}}{{8}}<\frac{{1}}{{2}}\usepackage{cmbright}\Huge\$ as well.