and answers 2025\2026 A+ Grade
Population
- correct answer The whole set of items that are of interest
Census
- correct answer Observes or measures every member of a population
Advantages of a census
- correct answer It should give a completely accurate result
Disadvantage of a census
- correct answer Time consuming and expensive
Hard to process large quantity of data
Sample
- correct answer A selection of observations taken from a subset of the population which is used to find
out information about the population as a whole
Advantages of a sample
- correct answer Less time consuming
Fewer people have to respond
Less data than a census
Disadvantage of a sample
- correct answer The data may not be as accurate
The data may not be large enough toggle information about the population
, Sampling Units
- correct answer Individual units of a population
Sampling Frame
- correct answer A list of individually named or numbered sampling units
Simple Random Sample
- correct answer A sample where every sampling unit has an equal chance of being chosen
Advantages of Simple Random Sample
- correct answer Free of bias
Easy and cheap to implement
Each sampling unit has equal chance of selection
Disadvantage of Simple Random Sample
- correct answer A sampling frame is needed
Not suitable when the population size is very big
Systematic Sampling
- correct answer A method of sampling where the required elements are chosen at regular intervals
from an ordered list
Advantages of Systematic Sampling
- correct answer Simple and quick to use
Suitable for large samples
Disadvantages of Systematic Sampling
- correct answer A sampling frame is needed
It can introduce bias if sampling frame is not random