\[\boxed{\mathbf{596.}\mathbf{\ }}\]
\[1)\ 300\ :100 \cdot 7 = 21\]
\[2)\ 10\ :100 \cdot 26 = 0,1 \cdot 26 = 2,6\]
\[3)\ 120\ :100 \cdot 30 = 1,2 \cdot 30 = 36\]
\[4)\ 62\ :100 \cdot 156 =\]
\[= 0,62 \cdot 156 = 96,72\]