Question

The number of accidents at a dangerous intersection in a Smalltown during each of the last six years is as follows: 0,1,1,2,3,5. For this data set, the standard deviation of the number of accidents in a year ( rounded to the nearest tenth) is

Answer 1

Solution:

x	x2
0	0
1	1
1	1
2	4
3	9
5	25
x = 12	x2 = 40

Sample standard deviation is   = (x² ((x)²/n)) n-1

=40 ((12)² / 6) 5

= 40 -24 /5

=16 / 5

= 3.2

= 1.8

Sample standard deviation is 1.8