Contrast a population, a sample, and a census.
A representative sample reflects the population fairly, whereas a biased sample systematically favours certain outcomes.
In systematic sampling, the sampling interval kkk is calculated by the formula k=Nnk = \boxed{\frac{N}{n}}k=nN (Population size / Sample size).
It only includes people available at that specific time (e.g., excludes those working 9-5).
Flashcards for Edexcel A Level Maths Data Collection, covering the key formulae, methods and definitions you need to recall for Paper 1, Paper 2 and Paper 3. 24 cards drawn from 1.1 Populations and Samples, 1.2 Sampling, 1.3 Non-Random Sampling, 1.4 Types of Data, and 1.5 The Large Data Set, matched to the Edexcel A Level Maths (9MA0) specification. Recall questions account for roughly 50% of marks at A Level Maths, so these target the marks you can secure before the paper starts.
