Question

If the standard deviation of $3$, $8$, $6$, $10$, $12$, $9$, $11$, $10$, $12$, $7$ is $2.71$, then the standard deviation of $30$, $80$, $60$, $100$, $120$, $90$, $110$, $100$, $120$, $70$ is

• A. $2.71$
• B. $27.1$
• C. $\left(2.71\right)\sqrt{10}$
• D. $\left(2.71\right)\sqrt{2}$

Answer 1

Answer: (B)

$27.1$

Answer 2

We know that, the standard deviation is dependent on scale. If the values in the sample are multiplied by $k$, then the standard deviation will be multiplied by $k$.
So, in given series/sample, multiplied by 10 , then the resulting standard deviation is
$=10 \times 2.71=27.1$