What is an IQR (Interquartile Range)?

The Interquartile Range (IQR) is recognized as the difference between the first quartile (Q1) and the third quartile (Q3) of a dataset. Q1 marks the value below which 25% of the data fall, while Q3 indicates the value below which 75% of the data fall. By calculating the IQR, you effectively measure the middle 50% of the data, providing a robust indicator of variability that is less influenced by outliers or extreme values. This helps identify the range in which the central half of the data lies and is critical for understanding the spread of the dataset.

Other options discuss average values or general variability measurements but do not define the IQR specifically. Option B suggests a focus on averages, which does not capture the essence of the IQR as a measure of range. Option C describes an average, not a range, and misses the specific quartile context. Option D mentions variability in general, but IQR specifically quantifies this variability by focusing on a defined segment of the dataset.