The interquartile range (IQR) is calculated as the difference between the third quartile ($Q_3$) and the first quartile ($Q_1$).

From the image:

• $Q_3 = 140$
• $Q_1 = 116$

$\text{IQR} = Q_3 - Q_1 = 140 - 116 = 24$

The interquartile range of the dataset is 24.

Would you like an explanation of how interquartile range helps measure spread in data?

Here are 5 related questions for you to consider:

1. What is the purpose of the interquartile range in statistics?
2. How is the interquartile range used to identify outliers in a dataset?
3. What is the difference between the interquartile range and the standard deviation?
4. How do you calculate $Q_1$ and $Q_3$ for a larger dataset?
5. Why might the interquartile range be more robust than the range?

Tip: Always verify that your $Q_1$ and $Q_3$ values are correct, as they directly affect the IQR calculation.