Given data:
375, 210, 150, 147, 429, 189, 320, 580, 407, 180
First, rearrange the data from lowest to highest, and we get the data set
147, 150, 180, 189, 210, 320, 375, 407, 429, 580
The IQR is determined by the formula
Therefore, the IQR of the data set is 227.