Notes

Sample Data vs Population Data

• Use different formulas for sample data and population data
• Population
  • Each data point is known, so 100% sure.
• Sample
  • Sample statistics is an approximation of the population perimeter.

Measures of Variability

• Variance

  • Measures the dispersion of a set of data points around their mean

  • Population

    

    • The closer the number to the mean, the lower the result we will obtain.
    • The further the number to the mean, the higher the result we will obtain.
    • By squaring number, we ger non-negative computations.

  • Sample

    

• Standard Deviation

• Coefficient of Variation

Dispersion cannot be negative.

• Non negative values don’t cancel out.
• Amplifies the effect of large differences.

Course Materials

2.9.+Variance_lesson.xlsx