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The standard deviation of first 10 multiples of 4 is
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Verified Answer
The correct answer is:
$11.5$
Entries are $4,8,12,16,20,24,28,32,36,40$.
$$
\begin{aligned}
\text { Variance } & =\frac{\sum_{i=1}^{10}(4 i)^2}{10}-\left(\frac{\sum_{i=1}^{10} 4 i}{10}\right)^2 \\
& =\frac{16 \times 10 \times 11 \times 21}{60}-\left(\frac{4 \times 55}{10}\right)^2 \\
& =132
\end{aligned}
$$
$\therefore$ Standard deviation $=\sqrt{132} \approx 11.5$
$$
\begin{aligned}
\text { Variance } & =\frac{\sum_{i=1}^{10}(4 i)^2}{10}-\left(\frac{\sum_{i=1}^{10} 4 i}{10}\right)^2 \\
& =\frac{16 \times 10 \times 11 \times 21}{60}-\left(\frac{4 \times 55}{10}\right)^2 \\
& =132
\end{aligned}
$$
$\therefore$ Standard deviation $=\sqrt{132} \approx 11.5$
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