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Shape and Space
Statistics and Probability
"Sampling" basically means selecting people/objects from a "population" in order to test the population for something. For example, we might want to find out how people are going to vote at the next election. Obviously we can't ask everyone in the country, so we ask a sample.
When considering a particular population it is usually advisable to choose a sample in such a way that everyone is represented. This is not easy and requires careful thought about sample size and composition. Often questionnaires are devised to identify the required information. These need to be idiot proof, so questions need to cover all alternatives and give little scope for variation.
A bus company attempted to estimate the number of people who travel on local
buses in a certain town. They telephoned 100 people in the town one evening and
asked 'Have you travelled by bus in the last week?'