Answer
$IQR=41~min$
It is the range of the middle 50% values of the given data.
Work Step by Step
The bottom half of the data: 48, 57, 63, 71. $Q_1$ is the median of these values.
$Q_1=\frac{57+63}{2}=60$
The top half of the data: 88, 93, 109, 111. $Q_3$ is the median of these values.
$Q_3=\frac{93+109}{2}=101$
$IQR=Q_3-Q_1=101-60=41$
