Interpreting Statistical Data (Copy)
Cheat Sheet: Reading, Interpreting, and Comparing Statistical Data (IGCSE Mathematics 0580 – CORE)
Topic: Tables, Graphs, Statistical Measures
1. Reading and Interpreting Tables and Diagrams
- Tables and diagrams show data in a visual or organized form.
- Common types:
- Frequency tables (show counts)
- Bar charts (show categories and frequencies)
- Pie charts (show proportions as sectors)
- Line graphs (show trends over time)
- Pictograms (use symbols for counts)
Key Points:
- Read titles, axes labels, and keys carefully.
- Check units (e.g., number of people, distance in km).
- Totals and averages may be hidden and need to be calculated.
2. Drawing Inferences from Data
- Make logical conclusions based on the data shown.
- Examples:
- Which category is most popular?
- Which group has the highest or lowest value?
- Are there any obvious trends?
3. Comparing Sets of Data
When comparing two sets of data:
| Statistical Measure | What it tells you |
|---|---|
| Mean (average) | Typical value, affected by extreme values. |
| Median | Middle value, resistant to extreme values. |
| Range | Spread between the highest and lowest values (variability). |
| Mode | Most common value (useful for categories). |
To compare:
- Compare averages (mean/median) to judge which data set is generally higher or lower.
- Compare ranges to judge which data set is more spread out (less consistent).
4. Restrictions on Drawing Conclusions
- Small samples may not represent the full population.
- Bias can exist if the data collection is unfair.
- Correlation does not mean causation (e.g., two things happening together doesn’t prove one causes the other).
- Always mention if conclusions are based on estimates or limited data.
5. Important Tips
- Use mean when data is balanced without extreme outliers.
- Use median when data has outliers or is skewed.
- Always check range to understand consistency:
- Small range = more consistent data.
- Large range = more variable data.
This cheat sheet fully covers CORE-level requirements for reading, interpreting, comparing, and making sensible conclusions from tables, graphs, and statistical data.