$\frac{3}{8}:\frac{5}{4}=\frac{3}{8}\times \frac{4}{5}=\frac{12}{40}= \frac{3}{10}$
$\frac{4}{7}:\frac{2}{13}=\frac{4}{7}\times \frac{13}{2}=\frac{52}{14}=\frac{26}{7}$
$\frac{3}{8}:\frac{5}{4}=\frac{3}{8}\times \frac{4}{5}=\frac{12}{40}= \frac{3}{10}$
$\frac{4}{7}:\frac{2}{13}=\frac{4}{7}\times \frac{13}{2}=\frac{52}{14}=\frac{26}{7}$