In this lesson, students represent distributions of numerical (and optionally categorical) data after organizing them into frequency tables. They construct dot plots for numerical data (and bar graphs for categorical data). Using graphical representations of distributions, they continue to develop a spatial understanding of distributions in preparation for understanding the concepts of “center” and “spread” in future lessons. Students make use of the structure of dot plots (MP7) to describe distributions and draw conclusions about the data.
- Comprehend the word “frequency” to refer to the number of times a particular value occurs in a data set.
- Create and interpret a dot plot to answer statistical questions about a numerical data set.
- Justify (in writing) whether a dot plot is an appropriate way to display a given data set, paying attention to whether the data set is numerical or categorical.
Let’s represent data with dot plots and bar graphs.
1 sticky note and 1 dot sticker for each student. Straightedges should be made available to create dot plots.
- I can describe the information presented in tables, dot plots, and bar graphs.
- I can use tables, dot plots, and bar graphs to represent distributions of data.
The distribution tells how many times each value occurs in a data set. For example, in the data set blue, blue, green, blue, orange, the distribution is 3 blues, 1 green, and 1 orange.
Here is a dot plot that shows the distribution for the data set 6, 10, 7, 35, 7, 36, 32, 10, 7, 35.
The frequency of a data value is how many times it occurs in the data set.
For example, there were 20 dogs in a park. The table shows the frequency of each color.
color frequency white 4 brown 7 black 3 multi-color 6