\[\boxed{\text{1221.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[\textbf{а)}\ 1,2 \cdot 10^{9}\]
\[n = 9\]
\[\textbf{б)}\ 3,6 \cdot 10³\]
\[n = 3\]
\[\textbf{в)}\ 2,7 \cdot 10^{- 3}\]
\[n = - 3\]
\[\textbf{г)}\ 6,3 \cdot 10^{- 1}\]
\[n = - 1\]
\[\textbf{д)}\ 4,42 \cdot 10^{5}\]
\[n = 5\]
\[\textbf{е)}\ 9,28 \cdot 10^{- 4}\]
\[n = - 4\]