1. **State the problem:** We are given a box plot with minimum 40, Q1 at 50, median at 60, Q3 at 70, and maximum 80. We need to find the interquartile range (IQR).
2. **Formula for IQR:** The interquartile range is calculated as $$\text{IQR} = Q3 - Q1$$ where $Q1$ is the first quartile and $Q3$ is the third quartile.
3. **Identify values:** From the box plot, $Q1 = 50$ and $Q3 = 70$.
4. **Calculate IQR:**
$$\text{IQR} = 70 - 50$$
5. **Simplify:**
$$\text{IQR} = 20$$
6. **Interpretation:** The interquartile range is 20, meaning the middle 50% of the data spans 20 units on the scale.
**Final answer:** The interquartile range (IQR) is 20.
Box Plot Iqr 2E7D11
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