WAEC - Mathematics (2019 - No. 41)

Calculate the variance of 2, 4, 7, 8 and 9 
7.2
6.8
3.5
2.6

Explanation

 

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

 

Comments (0)

Advertisement