Variability

Variance

• Position of each observation relative to the mean of the set.
• Measures the amount of spread or variability of observation from mean
• Useful statistic in certain high level of statistical procedure

standard deviation

• a measure of how spread out numbers are
• Square root of variance
• Widely used and better measure of variability
• Smaller value of standard deviation, the closer to the mean
• Sensitive to extreme value

Range

• difference between the lowest and highest values
• Tends to increase with sample size
• Sensitive to very extreme values

By : Fatin Farhana binti Marzuki

References

Retrieved on April 21, 

    2017 https://www.mathsisfun.com/data/standard-deviation-

    formulas.html

Retrieved on April 21, 

    2017 http://www.sciencebuddies.org/science-

    fairprojects/project_data_analysis_variance_       

    std_deviation.shtml

Retrieved on April 21, 

    2017 https://www.mathsisfun.com/data/range.html