To find these from the graph we draw two lines across ... the difference between the upper quartile and lower quartile. Interquartile range = upper quartile - lower quartile = 47 - 38 = 9 cm.
the lower quartile is 38. To find the upper quartile, find ¾ of 40, which is the 30th value. Reading from the graph, the upper quartile is 47. The interquartile range is the upper quartile ...