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Geographical skills theory
Measures of dispersion
Shows how various different measures indicate the extent to which data is
grouped around the mean.
Range- difference between the highest and lowest values. Can be misleading
if the highest and lowest values are extreme.
Interquartile range- works out the difference between the upper quartile
and the median and the lower quartile and the median. As it calculates the
data range either side of the median it avoids distortion caused by extreme