The shoe size for a varsity field hockey team are: 5.5, 5.5, 6, 6.5, 6.5, 7, 7, 7.5, 7.5, 7.5, 8, 8, 8, 8.5 8.5, 9. Which of the following is the IQR and explains how this measure variability describes how the value of the dataset vary with a single number