Statistics · Class 11 Commerce
Ch 1Collection of Data — Class 11 Statistics, concept-first.
Every statistical study — whether it is a shopkeeper tracking daily sales, the government estimating unemployment, or a company testing whether a new packaging design sells better — begins with the same first step: collecting data.
Key concepts
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Primary Data and Methods of Collection
Primary data is collected for the first time, directly for the purpose of the present study, using methods such as Direct Personal Investigation, Indirect Oral Investigation, the Mailed Questionnaire Method, the Schedule…
Most relevant Q&A
Chapter contents
The NCERT structure, section by section. Open a section to see its questions, then read the concept-first solution.
What Statistics Studies, and Why Data Collection Comes First
Every statistical study — whether it is a shopkeeper tracking daily sales, the government estimating unemployment, or a company testing whether a new packaging design sells better — begins with the sa…
Primary Data and Its Methods of Collection
Primary data is data collected for the first time, directly from the units of the investigation (people, households, firms), specifically for the purpose of the study at hand.
Secondary Data and Its Sources
Secondary data is data that already exists — it was collected by some other person, organisation, or agency for their own purpose, at an earlier time, and the present investigator simply makes use of…
Census Method versus Sample Method
Once it is decided that data must be collected, a further basic choice arises: should every single unit of the population be studied, or only a part of it?
The Questionnaire — Design and Editing of Data
A questionnaire is a formally structured list of questions prepared in advance to collect specific information from respondents, used in several of the primary-data methods above (mailed questionnaire…
Exercises
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- Q5Define primary data and secondary data, and give one example of each in the context of a study on the literacy rate of a district.Free
- Q6State whether each of the following is an example of the Census Method or the Sample Method: (i) The Election Commission verifies every sing…Free
- Q7List any four sources of secondary data, and state the four points an investigator should check before using secondary data collected by som…Preview
- Q8Explain why "editing of data" is a necessary step after data has been collected, and mention the three things an investigator checks for dur…Preview
More questions
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- Example 1A researcher wants to study the average monthly household expenditure of families living in a single mid-sized town. Should the researcher u…Free
- Example 2Classify each of the following as Primary Data or Secondary Data: (i) A student surveys 50 classmates directly to find their favourite subje…Free
- Example 3A government agency wants to collect data on annual income directly from 5,000 households spread across many remote villages, using trained…Preview
- Example 4Point out what is wrong with the following questionnaire item, and rewrite it as a better question: "Don't you agree that spending too much…Preview