Remember this only can occur if the data is put into an ordered format. The interquartile range (IQR) is an important concept in the context of constructing and using a box plot. The box plot is a ...

The interquartile range (IQR) is therefore 18 - 4 = 14 ... 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.

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 ...