Chapter 3 Descriptive Statistics

Chapter 3 Descriptive Statistics

Variance and Standard Deviation Calculations

Variance & Standard Deviation Variability Spread Dispersion Homogeneity/Heterogeneity

Common Central Tendencies….. Variability Spread Dispersion Homogeneity/Heterogeneity

Variance The didactic formula

S

2



 X

 X

n  1

The calculating formula

 X 

2

S2 

X

2



n 1

n



2

Variance and Standard Deviation

S2 

X

 X 

2

2



n 1

n

 X 

2

S 

X

2



n 1

n