Question

Find the standard deviation and sample variance

18,16,3,7,11

Answer 1

Solution:

x	x2
18	324
16	256
3	9
7	49
11	121
x=55	x2=759

The sample standard is S

  S =( x² ) - (( x)² / n ) n -1

=(759-(55)²5 )/4

=(759-605) /4

=154 /4

=38.5

=6.2048

The standard deviation = 6.20

Sample Variance S²=( x² ) - (( x)² / n ) n -1

=(759-(55)²5 )/4

=(759-605) /4

=154 /4

=38.5

sample variance = 38.5