答案：(a) 平均值 $=3.5$, 四分位數間距 $=2$, 標準差 $=1.5$ (b) $0.048\ 5$
- 平均值
$\begin{array}{cl}
= & 3.5
\end{array}$四分位數間距
$\begin{array}{cl}
= & 4-2 \\
= & 2
\end{array} $標準差
$\begin{array}{cl}
= & 1.5
\end{array}$ - 新的標準差
$\begin{array}{cl}
= & 1.451~456~116
\end{array}$所以，標準差的改變
$\begin{array}{cl}
= & 1.5 – 1.451~456~116 \\
= & 0.048~543~884
\end{array}$
