Population
- A collection of all items of interest (N)
- Populations are hard to define and observe in real life
Sample
- Subset of the population (n)
- A Sample is much easier to gather
- Less time-consuming and cheaper
Samples are key to accurate statistical insights. A Sample must be both Random and Representative for an accurate statistical insight.
Randomness: A random sample is collected when each member of the sample is chosen from the population strictly by chance
Representativeness: A Representative sample is a subset of the population that accurately reflects the members of the entire population