WAEC - Mathematics (2019 - No. 41)
Calculate the variance of 2, 4, 7, 8 and 9
7.2
6.8
3.5
2.6
Paliwanag
|
x 2 4 7 8 9 |
(\(\bar{x} - \bar{x}\)) -4 -2 1 2 4 |
(\(\bar{x} - \bar{x})^2\) 16 4 1 4 9 _________ \(\sum (x - x)^2\) = 34 |
\(\bar{x} = \frac{2 + 4 + 7 + 8 + 9}{5} = 6
variance = \(\frac{34}{5}\)
= 6.8