What distinguishes a census from a sample in market analysis?
Correct Answer
A) A census counts every member of the population
A census seeks to enumerate every member of the defined target population; a sample uses a subset. Complete accurate enumeration has no sampling error for that population, but collection, recording, coverage and measurement errors may remain. Neither random selection nor a fixed count such as 100 defines a census, and a target period must be specified rather than inferred from transaction age.
Why This Is the Correct Answer
Option A is correct because a census counts all members of the defined population, while a sample examines only a subset. A complete, accurate census has no sampling error for that population, although recording, coverage and measurement errors may still occur.
Why the Other Options Are Wrong
Option B: A census is drawn at random from the population
Option B, a census drawn at random from the population, describes a random sample rather than a census. A census does not select members; it includes all of them.
Option C: A census contains at least one hundred records
Option C, containing at least one hundred records, is not the definition of a census. A census is defined by complete coverage of the population, not by a minimum count.
Option D: A census excludes any transaction over a year old
Option D, excluding any transaction over a year old, describes a time filter, not a census. The target period is set by the analyst's definition of the population rather than by a fixed age rule.
Census means all in
A census includes the whole defined population; a sample includes only part of it. Size and randomness do not decide which one you have.
How to use: Use this to reject choices that define a census by randomness, size or age.
Exam Tip
Look for the choice about complete coverage of the defined population. Random selection describes sampling.
Common Mistakes to Avoid
- -Confusing random selection with a census
- -Believing a census requires a minimum number of records
- -Assuming a census is free of all types of error
Concept Deep Dive
Analysis
This question tests the definition of a census versus a sample. A census attempts to enumerate all members of the defined target population, while a sample uses only a subset; size thresholds, random selection or age cutoffs do not define a census.
Background Knowledge
Sampling error arises because a sample rather than a census of the population is used. A census eliminates sampling error for its population but can still contain non-sampling errors such as coverage or recording mistakes. Defining the target population, including its time period, comes before deciding between a census and a sample.
Real-World Application
An analyst studying a small condominium project uses all 40 sales in the defined period rather than a subset. Because the full defined population is included, there is no sampling error, though the analyst still checks the records for errors.
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