Statistics and Probability
Sampling from a population
People process large amounts of information every day. When we read newspapers, watch television or open our mail, we are often looking at information that has been organised in such a way that we can understand it easily. For example, we can easily tell how much water we use at home by looking at the information provided on our water bill.
When we collect, organise, represent and analyse information, we are using statistics. The information that is collected is called data. Statisticians work with data.
Analysing statistical data can help us understand more about a group of people, the habits of animals or changes in the weather over time. This information helps us make decisions and predict outcomes.
One very important aspect of statistics is collecting representative data. This can be done by taking a census or survey, or by recording data through observations. In many instances it is not possible to take a census, so a sample of the population is selected and surveyed, and conclusions are then drawn for the whole population.