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Key Stage 3 Statistics
Grouped Data
Use grouped frequency tables and grouped charts to summarise data.
Key idea
Look at the data type, choose an appropriate summary or diagram, then interpret the result in context.
What you will learn
Use class intervals confidently.
Use frequency confidently.
Use midpoints confidently.
Use grouped charts confidently.
Success checklist
✓I can explain what grouped data means.
✓I can choose a suitable method without being told.
✓I can show clear working and check my answer.
Worked example
Find the mean of 4, 7, 9 and 10.
Step 1
Add the values: 4 + 7 + 9 + 10 = 30.
Step 2
There are 4 values.
Step 3
30 ÷ 4 = 7.5.
Answer
7.5
Quick practice
Question 1
Find the median of 3, 8, 4, 10, 5.
Question 2
Find the range of 11, 18, 23, 24.
Question 3
Describe positive correlation in a scatter graph.
Related resources
These are linked to the wider Statistics topic for now.