Question

The standard deviation of $1,3,5,7$ is

• A. $\sqrt{3.5}$
• B. $\sqrt{5}$
• C. $\sqrt{3}$
• D. $\sqrt{2}$

Answer 1

Answer: (B)

Mean $=\frac{1+3+5+7}{4}=4$
$\therefore$ Variance
$=\sum _{i=1}^4\frac{(x_i-\bar{x}{)}^2}{n}$
$=\frac{(-3{)}^2+(-1{)}^2+(1{)}^2+3^2}{4}=5$
So, standard deviation $=\sqrt{5}$