Решение:
\[ 1\frac{5}{9} - \frac{4}{7} = \frac{14}{9} - \frac{4}{7} = \frac{14 \times 7 - 4 \times 9}{9 \times 7} = \frac{98 - 36}{63} = \frac{62}{63} \]
\[ 3\frac{4}{9} : \frac{62}{63} = \frac{31}{9} : \frac{62}{63} = \frac{31}{9} \times \frac{63}{62} \]
\[ \frac{31}{9} \times \frac{63}{62} = \frac{31}{62} \times \frac{63}{9} = \frac{1}{2} \times \frac{7}{1} = \frac{7}{2} = 3\frac{1}{2} \]
Ответ: \[ 3\frac{1}{2} \]