AQA GCSE · Question 11.2 · Data Visualization and Representation
On the grid draw a cumulative frequency diagram for the data.
How to approach this question
1. Use the cumulative frequency table from the previous part.
2. For a cumulative frequency graph, you plot the cumulative frequency against the **upper class boundary** of each group.
3. The points to plot are (upper boundary, cumulative frequency).
4. The first point is (5, 8).
5. The second point is (10, 31).
6. The third point is (15, 71).
7. The fourth point is (20, 90).
8. The fifth point is (25, 100).
9. The graph should start from the lowest boundary with a frequency of 0, so start your line at (0, 0).
10. Plot all the points and connect them with a smooth curve or straight lines.
Full Answer
A cumulative frequency diagram plots the cumulative frequency against the upper class boundary for each group. The graph should always start at the lowest boundary with a cumulative frequency of zero.
The points to be plotted are:
- (0, 0) - The starting point
- (5, 8)
- (10, 31)
- (15, 71)
- (20, 90)
- (25, 100)
After plotting these points accurately on the grid, they should be joined with a smooth, S-shaped curve (ogive) or with straight line segments.
Common mistakes
✗ Plotting points at the midpoint of the class interval instead of the upper boundary.\n✗ Misreading the scales on the axes.\n✗ Not starting the graph at (0,0).
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