Question

The S.D. of 5 scores 1, 2, 3, 4, 5 is

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

Answer 1

Answer: (C)

$\sqrt{2}$

Answer 2

Mean $\bar{x} = \frac{1 + 2 + 3 + 4 + 5}{5} = 3$

S.D.=$\sigma$ =$\sqrt{\frac{1}{n}\sum_{}^{}{x_{i}^{2} - (\bar{x}})^{2}}$

=$\sqrt{\frac{1}{5}(1 + 4 + 9 + 16 + 25) - 9}$=$\sqrt{11 - 9} = \sqrt{2}$.