StatisticsLesson 53Free preview
Variability
This lesson is part of A.I. · All levels
Summary
Variance and standard deviation measure how far the data values spread from their mean. The variance is the square root of the difference of each value to the mean, whereas the standard deviation is the square root of the variance. Data with large cross-sections contains very variable values.
Key points
- Variance measures the spread of data against the mean.
- Standard deviation = square root of variance, the unit is equal to the data.
- Zero variance means all data values are identical.
- The large standard deviation indicates that the data is highly variable.
- Measuring variables is important when evaluating data quality.
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