Answer:
6
Explanation:
First, ensure the numbers are ordered in ascending order:
[tex]4,15,17,18,20,21,23,25[/tex]Since we have an even number of items, divide the items into two equal parts:
[tex](4,15,17,18,)(20,21,23,25)[/tex]For the lower quartile, find the median of the lower half:
[tex]Q_1=\frac{15+17}{2}=\frac{32}{2}=16[/tex]For the upper quartile, find the median of the upper half:
[tex]Q_3=\frac{21+23}{2}=\frac{44}{2}=22[/tex]Finally, find the interquartile range:
[tex]\begin{gathered} \text{IQR}=Q_3-Q_1 \\ =22-16 \\ =6 \end{gathered}[/tex]The interquartile range for the data set is 6.
