Question

The variance of the data 2, 4, 6, 8, 10 is

• A. 6
• B. 7
• C. 8
• D. None of these

Answer 1

Answer: (C)

8

Answer 2

Here, $\bar{x} = \frac{2 + 4 + 6 + 8 + 10}{5} = 6$

Hence, variance = $\frac{1}{n}\Sigma(x_{i} - \overline{x})^{2}$

$= \frac{1}{5}\{(2 - 6)^{2} + (4 - 6)^{2} + (6 - 6)^{2} + (8 - 6)^{2} + (10 - 6)^{2}\}$

$= \frac{1}{5}\left\{ (16 + 4 + 0 + 4 + 16 \right\} = \frac{1}{5}\left\{ 40 \right\}$ $= 8$.