Question

The following data are to be used for answering this question

20	1	5
1	9	9
10	2	6

What is the variance of this population of scores?

		5.6
		30
		32
		36
		288

Answer 1

Solution :

Data : 20 , 1, 5 , 1 , 9 , 9 , 10 , 2 , 6

n = 9

mean = = x / n = (20 + 1 + 5 + 1 + 9 + 9 + 10 + 2 + 6) / 9

= 63 / 9

= 7

mean = = 7

variance = (x - )² / n

= (20 - 7)² + (1 - 7)² + (5 - 7)² + (1 - 7)² + (9 - 7)² + (9 - 7)² + (10 - 7)² + (2 - 7)² + (6 - 7)² / 9

= 288 / 9

=32

The variance of this population  of scores = 32