Lesson objective: Compare two populations using the median and interquartile range (IQR).

Students bring prior knowledge of displaying numerical data in plots on a number line, including dot plots, histograms, and box plots from 6.SP.B.4. This prior knowledge is extended to a visual and numerical understanding of data as students compare data from two populations. A conceptual challenge students may encounter is comparing data from one population to another at a singular point instead of comparing the measures of center and variability of the two populations.

The concept is developed through work with dot plots and box plots, which allow for a visual understanding and comparison of multiple populations.

This work helps students deepen their understanding of operations because they are challenged to compute measures of center and variability to provide a more detailed understanding of data.

Students engage in Mathematical Practice 4 (model with mathematics) as they utilize different forms of visual representations to more deeply analyze data of two populations.

**Key vocabulary:**

- mean
- median
- mean absolute deviation (MAD)
- interquartile range (IQR)
- box plot
- dot plot

**Special materials needed:**