Ответ:

\[1.2:0.3=4.\]

\[\frac78-\frac1{16}=\frac{14}{16}-\frac1{16}=\frac{13}{16}.\]

\[\frac{4}{\left(\frac{13}{16}\right)\cdot3.2}=\frac{4}{\frac{13}{16}\cdot\frac{16}{5}}=\frac{4}{\frac{13}{5}}=\frac{20}{13}.\]

Ответ: \(\dfrac{20}{13}\).