§ Задание 78
\[\boxed{\mathbf{3.78}}\]

\[\frac{4}{16} = \frac{5}{20}\]
\[\frac{16}{4} = \frac{20}{5}\]
\[\frac{4}{5} = \frac{16}{20}\]
\[\boxed{\mathbf{3.78}}\]

\[\frac{4}{16} = \frac{5}{20}\]
\[\frac{16}{4} = \frac{20}{5}\]
\[\frac{4}{5} = \frac{16}{20}\]