The interquartile range is another measure of spread ... so the UQ is the 30th number. To find these from the graph we draw two lines across from the vertical axis, one at 10 and one at 30.

While all values in a data set are used to calculate the mean, only the interquartile range -- the central portion of a data set -- is used to calculate the interquartile mean. Microsoft Excel has ...

The interquartile range shows the range in values of the central 50% of the data. To find the interquartile range, subtract the value of the lower quartile (\(\frac{1}{4}\) or 25%) from the value ...