Answer
$IQR=4.15~miles~per~gallon$
It is the range of the middle 50% values of the given data. In this case, it contains the 12 middle observations: 37.4, 37.5, 37.8, 37.9, 38.0, 38.3, 38.4, 38.8, 39.3, 39.5, 40.1, 40.6
Work Step by Step
$IQR=Q_3-Q_1=41.0-36.85=4.15$
