Final answer:
The interquartile range (IQR) of the given data set is 10 feet.
Step-by-step explanation:
The interquartile range (IQR) is the difference between the third quartile (Q3) and the first quartile (Q1) and it represents the spread of the middle half of the data. To calculate the IQR, we subtract Q1 from Q3. In this case, the first quartile is 400 and the third quartile is 410, so the IQR is 410 - 400 = 10 feet.