Page 100 - Knowledge Organiser Yr9 24-25

Knowledge Base: Mathematics Topic 32: Interpreting Data Year 9 | Spring Term, 2nd Half
By the end of this topic you should be able to:
• Understand and work out averages and range.
• Find averages from tables
• Draw frequency tables for continuous data
• Find averages from grouped data
• Plot and interpret pie charts
• Interpret statistical diagrams
Language
Meaning
Example
Average
A measure of the typical valueof data.
The mode, median and mean are averages.
Frequency tables
Used to show the amount of data in each group.
Scatter diagram
A graph showing paired data plotted (x, y) points.
Correlation
A relationship between two variables, that can be positive or negative.
As the temperature increases, the number of ice creams sold increases. This is a positive correlation.
Important things to remember:
1) To find an estimate of the mean from group frequency data use the midpoint of each group
2) To compare groups of data use an average to compare typical values and the range to show the spread of data
Worked examples
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