19.6. Measures of Variability
19.6.1 Range
19.6.2 Interquartile Range and Quartile Deviation
19.6.3 Mean Absolute Deviation
19.6.4 Variance and Standard Deviation
19.6.5 Coefficient of Variation
Measures of variability tells us the spread of a distribution relative to the mean. The most common measures are: range, mean absolute deviation, interquartile range, standard deviation, variance, and coefficient of variation.
Range - the distance between the lowest and highest values in a data set
Mean absolute deviation - the average of the distances between each data point and the mean
Interquartile range (IQR) - the range of the middle 50% of the distribution
Standard deviation - the square root of the average squared distances between each data point and the mean
Variance - the average of the squared distances between each data point and the mean
Coefficient of variation - the percentage of the standard deviation relative to the mean of the data set
Range - the distance between the lowest and highest values in a data set
Mean absolute deviation - the average of the distances between each data point and the mean
Interquartile range (IQR) - the range of the middle 50% of the distribution
Standard deviation - the square root of the average squared distances between each data point and the mean
Variance - the average of the squared distances between each data point and the mean
Coefficient of variation - the percentage of the standard deviation relative to the mean of the data set
