The interquartile range of a set of data is __________. A. the difference of the upper and lower quartiles of the data set B. the difference of the maximum and minimum values of the data set C. the difference between the upper quartile and minimum value of the data set D. the difference between the maximum value and the lower quartile of the data set
For example
First list the values in order:
3 4 5 7 9 10 18
2
4 + = th value.
Median = 7.
4
2 + = nd value.
Lower quartile = 4.
The upper quartile will be the 37 1
4
6 ( ) + = th value.
Upper quartile = 10.
The interquartile range = upper quartile – lower quartile
= 10 4 −
= 6
The semi-interquartile range = interquartile range
2
= 6
2
= 3