Arrange the data in ascending order
Find the median of the data set
Find the median of the lower half of the data set; this is Q1
Find the median of the upper half of the data set; this is Q3
Subtract Q1 from Q3
Interquartile Range = Q3 – Q1
Arrange the data in ascending order
Find the median of the data set
Find the median of the lower half of the data set; this is Q1
Find the median of the upper half of the data set; this is Q3
Subtract Q1 from Q3
Interquartile Range = Q3 – Q1