Organizing Data: Tables and Graphs
Making data easy to see
Why organize data?
Raw data can be hard to understand. Tables and graphs help reveal patterns, trends, and unusual values.
A frequency table
| Category | Count |
|---|---|
| Red | 5 |
| Blue | 8 |
| Green | 3 |
Common graphs
Bar charts are useful for categories, histograms show the distribution of numerical data, line graphs show change over time, and scatter plots show relationships between two numerical variables.
Graph choices
Bar chart
- Best for categories
- Bars are separated
Histogram
- Best for numerical intervals
- Bars touch because data are grouped into bins
Graph reading rule
Always check the title, axes, units, and scale before interpreting a graph.
Which graph is best for showing categories like favorite fruit?
Bar charts are ideal for categorical data.
Correct answer: Bar chart
What is the purpose of a frequency table?
Frequency tables summarize counts in an organized way.
Correct answer: To show how often each value or category appears.
Which graph is most appropriate for a relationship between two numerical variables?
Scatter plots show how two numerical variables move together.
Correct answer: Scatter plot
Name one thing you should check before trusting a graph.
These details affect how the graph should be interpreted.
Correct answer: The axes, scale, title, or units.