Cheat sheet · Class 11 · CBSE · Commerce Economics
Statistics: Collection of Data cheat sheet
The whole chapter on one page: key formulas, facts and the points to remember, for quick revision before a test.
CBSE Class 11 · Economics
Cheat sheet
Chapter 2Statistics: Collection of Data
Primary = collected by you; Secondary = collected by someone else.
1. Sources
| Type | Meaning | Example |
|---|---|---|
| Primary | first-hand, original | survey, interview |
| Secondary | already collected | Census, NSSO reports |
2. Methods of Survey
- Personal interview (accurate, costly).
- Mailing questionnaire (cheap, low response).
- Telephone interview.
- Pilot survey tests the questionnaire first.
3. Census vs Sample
| Basis | Census | Sample |
|---|---|---|
| Covers | every unit of the population | a representative part |
| Cost & time | high | low |
| Accuracy | high (if done well) | depends on sampling |
Random sampling: each unit has an equal chance (lottery, random tables). Non-random: judgement, quota, convenience.
4. Errors
- Sampling error: sample vs population difference.
- Non-sampling errors: measurement, non-response, sampling bias.
5. Key Points
- Census of India: every 10 years.
- NSSO: National Sample Survey Office.
- Questions should be short, clear, unbiased.
- Bigger samples reduce sampling error.
Remember: Primary vs secondary | census vs sample | errors
Statistics: Collection of Data: questions and notes
More Class 11 · CBSE · Commerce Economics cheat sheets
- Statistics: Introduction
- Statistics: Collection of Data
- Statistics: Organisation of Data
- Statistics: Presentation of Data
- Statistics: Measures of Central Tendency
- Statistics: Correlation
- Statistics: Index Numbers
- Microeconomics: Introduction
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- Microeconomics: Production and Costs
- Microeconomics: The Theory of the Firm under Perfect Competition
- Microeconomics: Market Equilibrium
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