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Single measurement variables

Students can measure and represent data collected about themselves.

They can then be asked to speculate about whether these measurements would represent a larger population (such as all students in their year across Australia) leading to an informal inference.

This relies on careful definitions of the sample and population, appreciating the most appropriate graphical representation, and knowing which measures of centre and spread will summarise the sample data.

Using this evidence to make an informal inference, students must realise that their conclusion cannot be made with absolute certainty because of the gap between their sample and the population.

Students might collect data on

Balancing act 1

Results from class investigations about balancing on one foot are used to make inferences about different groups or larger populations.

Signature length 1

Data collected from class investigations about signature lengths are used to make predictions about larger populations. 


This investigation uses a tag-release-recapture method to estimate the number of paperclips in a container. The resource includes a student worksheet, video clip and student work sample.

Curriculum links

Year 8: Explore the practicalities and implications of obtaining data through sampling using a variety of investigative processes

Year 9: Compare data displays using mean, median and range to describe and interpret numerical data sets in terms of location (centre) and spread

Year 10: Construct and interpret box plots and use them to compare data sets