why choose range or interquartile range
Interquartile range. The interquartile range is another range used as a measure of the spread. The difference between upper and lower quartiles (Q 3 âQ 1), which is called the interquartile range, also indicates the dispersion of a data set.The interquartile range spans 50% of a data set, and eliminates the influence of outliers because, in effect, the highest and lowest quarters are removed.emi-quartile range. The semi-quartile range is another measure of spread. It is calculated as one half the difference between the 75th percentile (often called Q 3) and the 25th percentile (Q 1). The formula for semi-quartile range is: (Q 3 âQ 1) Ã· 2.