Dispersion

It is the second dimension
How the data is dispersed, it is more clustered or spread out
Some estimates:
- Mean Absolute Deviation
  - Sensitive to outlier
- Variance → Most used by statistical application
  - Sensitive to outlier
  - Degrees of Freedom
- Standard Deviation → Most used by statistical application
  - Easy to interpret
  - Sensitive to outlier
- Median Absolute Deviation
  - Robust to outlier
Work with squared values is better than work with absolute values, specially in statistics
Values in size order: standard deviation > mean absolute deviation > median absolute deviation

Percentiles

It sorts data by its value
Percentile P means: P percent of values is below P and (100 - P) is above P
Median: percentile 50th
Quantile 0.8 = 80 percentile
Variability: difference between 25th and 75 percentile (Interquartile Range - IQR)