The following are the masses (in kg) of members in a club: 59, 44, 53, 49, 57, 40, 48, and 50. Calculate the variance of the distribution.
-
35
- 36
- 40
- 50
The correct answer is: A
Explanation
Variance(s\(^2\)) = \(\frac{\sum{(x - \overline{x})^2}}{n}\)
But mean = 50 (from question 39 same information)
|
x |
x - \(\overline{x}\) |
(x - \(\overline{x})^2\) |
| 59 | 9 | 81 |
| 44 | - 6 | 36 |
| 53 | 3 | 9 |
| 57 | 7 | 49 |
| 49 | - 1 | 1 |
| 40 | -10 | 100 |
| 48 | - 2 | 4 |
| 50 | 0 | 0 |
\(\sum{(x - \overline{x})^2}\) = 280
Variance(s\(^2\)) = \(\frac{\sum{(x - \overline{x})^2}}{n}\) = \(\frac{280}{8}\) = 35