Data Representation
5 minQuiz at the end
Choosing the Right Chart
| Chart type | Best for |
|---|---|
| Bar chart | Comparing discrete categories |
| Pie chart | Showing proportions of a whole |
| Histogram | Grouped continuous data |
| Frequency polygon | Comparing distributions |
| Stem-and-leaf | Displaying all values, showing distribution |
| Line graph | Data over time |
Bar Charts
Each bar's height = frequency. Bars are separated (for discrete/categorical data).
Pie Charts
Each sector's angle = (frequency / total) Γ 360Β°
Histograms
Used for grouped continuous data. The key difference from bar charts:
- No gaps between bars (data is continuous)
- Bar height = frequency density = Frequency Γ· Class width
- Area of each bar represents frequency
Frequency Polygons
Connect the midpoints of histogram bars with straight lines. Good for comparing two distributions on the same axes.
Stem-and-Leaf Diagrams
Display actual data values while showing the shape of the distribution:
3 | 2 5 7
4 | 1 3 6 9
5 | 0 2
Key: 3|2 means 32
Back-to-back stem-and-leaf diagrams compare two data sets.