In: Statistics and Probability
The number of sample orders written during each of the last 10 days are listed below.
3,6,9,8,7,4,6,5,1,1. Determine population standard deviation and sample variance
Solution:
Given that,
x | x2 |
3 | 9 |
6 | 36 |
9 | 81 |
8 | 64 |
7 | 49 |
4 | 16 |
6 | 36 |
5 | 25 |
1 | 1 |
1 | 1 |
x = 50 | x 2 = 318 |
a ) The population variance 2
2 =x - (( x )2 / n ) / n )
= ( 318 -( (50 )2 / 10 ) / 10
= 318 - 250/ 10
= 68 / 10
= 6.8
The population variance 2 = 6.8
b ) The population standard deviation is
= The population variance
= 6.8
= 2.61
The population standard deviation is = 2.61
c ) The sample variance S2
=x - (( x )2 / n ) / n-1 )
= ( 318 -( (50 )2 / 10 ) / 9
= 318 - 250/ 9
= 68 / 9
S2 = 7.56
The sample variance S2 is 7.56