Edexcel Maths A level Statistics Ch 1
Population
The whole set of items that are of interest
Census
Observes or measures every member of a population
Census (advantages and disadvantages)
Advantage:
- Gives a completely accurate result
Disadvantage:
- Time consuming and expensive
- Can't be used if process destroys the item
- Hard to process a lot of data
Sample
A selection of observations taken from a subset of the population which is used to find
information about the population as a whole
Sample (advantages and disadvantages)
Advantages:
- Less time consuming and expensive
- Fewer people have to respond
- Less data to process
Disadvantages:
- The data may not be accurate
- Sample may not be large enough to give information about small subsets
Effects of sample size
- The larger the sample the more accurate (but you require more resources)
- If the population is varied you need a larger sample than if it were uniform
- Different samples can lead to different conclusions due to natural variation
Population
The whole set of items that are of interest
Census
Observes or measures every member of a population
Census (advantages and disadvantages)
Advantage:
- Gives a completely accurate result
Disadvantage:
- Time consuming and expensive
- Can't be used if process destroys the item
- Hard to process a lot of data
Sample
A selection of observations taken from a subset of the population which is used to find
information about the population as a whole
Sample (advantages and disadvantages)
Advantages:
- Less time consuming and expensive
- Fewer people have to respond
- Less data to process
Disadvantages:
- The data may not be accurate
- Sample may not be large enough to give information about small subsets
Effects of sample size
- The larger the sample the more accurate (but you require more resources)
- If the population is varied you need a larger sample than if it were uniform
- Different samples can lead to different conclusions due to natural variation
