"Unit 2: Collection, Organisation and Presentation of data." : Class 11 : Economics
Multiple-Choice Questions (MCQs)
1. Which of the following is an example of a primary source of data?
a) Data obtained from a government census report.
b) Data obtained from a research paper published in a scientific journal.
c) Data obtained by interviewing 100 people about their spending habits.
d) Data obtained from a newspaper article.
Answer: c) Data obtained by interviewing 100 people about their spending habits.
Rationale: Primary data is collected directly by the researcher for a specific purpose, as opposed to secondary data which is already available from other sources.
2. Which of the following is not a characteristic of secondary data?
a) It is readily available.
b) It is less expensive to obtain.
c) It is more reliable than primary data.
d) It can be obtained from sources like the Census of India.
Answer: c) It is more reliable than primary data.
Rationale: The reliability of secondary data depends heavily on the source from which it was collected, and it may not be as reliable or relevant as data collected firsthand for the specific study.
3. The National Sample Survey Organisation (NSSO) in India primarily collects data related to:
a) National income and expenditure.
b) Social, economic, and demographic conditions.
c) Geological and weather patterns.
d) International trade statistics.
Answer: b) Social, economic, and demographic conditions.
Rationale: The NSSO is a key government organization in India that conducts nationwide surveys on various socio-economic issues.
4. Which method of data collection involves a researcher asking questions to a pre-defined set of people?
a) Direct personal investigation.
b) Indirect oral investigation.
c) Mailed questionnaire method.
d) Telephonic interviews.
Answer: a) Direct personal investigation.
Rationale: In a direct personal investigation, the investigator personally contacts the respondents and collects information through interviews.
5. A researcher wants to study the average income of households in a city. Instead of surveying every household, they survey a small group that represents the whole city. This group is called a:
a) Population.
b) Variable.
c) Sample.
d) Frequency distribution.
Answer: c) Sample.
Rationale: A sample is a smaller, representative group selected from a larger population for a study.
6. Which of the following is an example of a discrete variable?
a) The height of a student.
b) The temperature in a room.
c) The number of siblings a person has.
d) The weight of a bag of rice.
Answer: c) The number of siblings a person has.
Rationale: A discrete variable can only take specific, distinct values (like whole numbers), while the others are continuous variables that can take any value within a range.
7. A table that shows how many times each value or range of values appears in a dataset is called a:
a) Tabular presentation.
b) Frequency distribution.
c) Bar diagram.
d) Time series graph.
Answer: b) Frequency distribution.
Rationale: A frequency distribution organizes raw data into a table with classes or values and their corresponding frequencies.
8. What type of diagram is best suited for showing the components of a whole (e.g., different types of expenditures in a budget)?
a) Bar diagram.
b) Histogram.
c) Pie diagram.
d) Ogive.
Answer: c) Pie diagram.
Rationale: A pie diagram (or circle graph) represents the parts of a whole, where the size of each sector corresponds to its proportion of the total.
9. Which of the following diagrams is used for the presentation of continuous data?
a) Bar diagram.
b) Pie diagram.
c) Histogram.
d) Arithmetic line graph.
Answer: c) Histogram.
Rationale: A histogram is a graphical representation of a frequency distribution for continuous data, where the bars are adjacent to each other.
10. A frequency polygon is constructed by connecting the midpoints of the tops of the bars of a:
a) Bar diagram.
b) Histogram.
c) Pie diagram.
d) Ogive.
Answer: b) Histogram.
Rationale: A frequency polygon is an alternative way to represent continuous data, created by joining the midpoints of the histogram's bars with straight lines.
11. An Ogive is a graphical representation of:
a) A frequency distribution.
b) A time series graph.
c) A cumulative frequency distribution.
d) A bar diagram.
Answer: c) A cumulative frequency distribution.
Rationale: An Ogive (or cumulative frequency curve) shows the cumulative frequency of data, plotted against the upper class limits of a frequency distribution.
12. Which type of diagram is most suitable for showing the change in a variable over a period of time?
a) Bar diagram.
b) Pie diagram.
c) Histogram.
d) Arithmetic line graph.
Answer: d) Arithmetic line graph.
Rationale: An arithmetic line graph is specifically used to plot and analyze data that changes over time, such as stock prices or temperature fluctuations.
13. The term "variable" in statistics refers to a characteristic that can:
a) Be measured and assume a different value in different cases.
b) Only be a numerical value.
c) Only be a non-numerical value.
d) Only be a constant.
Answer: a) Be measured and assume a different value in different cases.
Rationale: A variable is any characteristic, number, or quantity that can be measured or counted, and which can change over time or for different individuals.
14. In a tabular presentation of data, what is the main purpose of the "body" of the table?
a) To provide the table's title.
b) To show the column headings.
c) To present the data in rows and columns.
d) To explain the sources of data.
Answer: c) To present the data in rows and columns.
Rationale: The body is the core part of the table that contains the numerical information or data values.
15. Which of the following is a type of diagrammatic presentation that can be either a simple, multiple, or component bar diagram?
a) Pie diagram.
b) Frequency polygon.
c) Bar diagram.
d) Ogive.
Answer: c) Bar diagram.
Rationale: Bar diagrams are versatile and can be used to compare a single set of data (simple), multiple sets of data (multiple), or the components of a set of data (component).
Short Answer Questions
1. Differentiate between primary and secondary sources of data.
Answer: Primary data is original data collected for a specific purpose by an investigator, such as through surveys or experiments. Secondary data is data that has already been collected by someone else and is available from published or unpublished sources, like government reports or research papers.
2. What is a sample, and why is sampling an important concept in data collection?
Answer: A sample is a smaller, representative subset of a population selected for a study. Sampling is important because it is often impractical, time-consuming, and expensive to collect data from the entire population. A well-chosen sample can provide reliable information about the entire population.
3. List two important sources of secondary data in India mentioned in your chapter.
Answer: Two important sources are the Census of India and the National Sample Survey Organisation (NSSO).
4. Explain the difference between a discrete variable and a continuous variable with an example for each.
Answer: A discrete variable can only take specific, separate values (e.g., number of students in a class), while a continuous variable can take any value within a given range (e.g., the height of a person).
5. What is a frequency distribution, and what is its main purpose?
Answer: A frequency distribution is a table that organizes raw data into classes or groups and shows the number of times each value or group appears. Its main purpose is to make a large dataset more manageable and easy to understand.
6. What are the two main types of diagrammatic presentation of data?
Answer: The two main types are Geometric forms (bar diagrams and pie diagrams) and Frequency diagrams (histogram, polygon, and Ogive).
7. What is the key difference between a bar diagram and a histogram?
Answer: A bar diagram is used for discrete or qualitative data, and there is a gap between the bars. A histogram is used for continuous data, and the bars are placed adjacent to each other without any gaps.
8. What is an Ogive, and what kind of information does it show?
Answer: An Ogive is a graphical representation of a cumulative frequency distribution. It shows the number of observations that are less than or greater than a particular value.
9. How is an arithmetic line graph different from the other diagrams you have studied?
Answer: An arithmetic line graph is specifically used to show the trend or change in a variable over a period of time, whereas other diagrams like bar charts and pie charts are generally used for comparison or showing parts of a whole at a single point in time.
10. Define the term "data."
Answer: Data is a set of facts, figures, and observations collected for a specific purpose. It can be numerical (quantitative) or descriptive (qualitative).
11. What is the purpose of "Organisation of Data"?
Answer: The purpose of organizing data is to arrange the raw, unclassified data into a more systematic and meaningful form, which makes it easier to analyze and interpret.
12. Explain the concept of "sampling" in the context of data collection.
Answer: Sampling is the process of selecting a representative group or subset from a large population to conduct a survey or study. It is a cost-effective and time-saving method to gather information about the entire population.
13. What is a variable in statistics?
Answer: A variable is any characteristic, attribute, or quantity that can assume different values. Examples include height, weight, age, or number of family members.
14. How do you construct a frequency polygon?
Answer: A frequency polygon is constructed by plotting the midpoints of the class intervals on the x-axis and the corresponding frequencies on the y-axis. These points are then joined by straight lines to form the polygon.
15. What is the purpose of the "source note" in a tabular presentation of data?
Answer: The source note is an important part of a table that specifies the source from which the data was collected. This helps in assessing the authenticity and reliability of the data.
Long Answer Questions
1. Discuss the different methods of collecting primary data, highlighting their merits and demerits.
Answer: The main methods of collecting primary data are:
Direct Personal Investigation: The investigator personally collects the data.
Merits: High degree of accuracy, flexible.
Demerits: Costly, time-consuming, limited coverage.
Indirect Oral Investigation: Data is collected from third parties who are likely to have the necessary information.
Merits: Wide coverage, less expensive.
Demerits: Less accurate due to reliance on others' information.
Mailed Questionnaire Method: Questionnaires are sent to respondents who fill them out and return them.
Merits: Wide coverage, inexpensive.
Demerits: Low response rate, requires literacy, possibility of misinterpretation.
Telephonic Interviews: Data is collected through phone calls.
Merits: Quick, inexpensive.
Demerits: Limited to people with phones, possibility of bias, no visual contact.
2. Explain the process of converting raw data into a frequency distribution. What are the key components of a frequency distribution table?
Answer: The process of converting raw data to a frequency distribution involves:
Finding the Range:
Calculating the difference between the maximum and minimum values.
Determining Class Intervals:
Deciding the size and number of groups (classes) for the data.
Tallying:
Counting the number of observations that fall into each class interval.
Creating the Table: Presenting the data in a table with columns for class intervals, tally marks, and frequency.
The key components of a frequency distribution table are:
Class Intervals: The ranges into which the data is grouped.
Tally Marks: The marks used to count the frequency of data in each class.
Frequency: The number of observations in each class interval.
3. Describe the different types of bar diagrams and explain when each type is best used.
Answer: The different types of bar diagrams are:
Simple Bar Diagram: Used to compare two or more items related to a single characteristic, such as production of a commodity in different years.
Multiple Bar Diagram: Used to compare two or more sets of interrelated data, such as sales and profit of a company over different years.
Component Bar Diagram: Used to show the relationship between different parts of a whole and the total, such as the division of total costs into different components.
4. Explain the purpose and construction of a Histogram and a Frequency Polygon. What are the advantages of using a Frequency Polygon over a Histogram?
Answer:
Histogram: A graphical representation of a continuous frequency distribution. It is constructed by drawing adjacent bars for each class interval, with the width representing the class width and the height representing the frequency. Its purpose is to show the distribution of continuous data.
Frequency Polygon: An alternative to the histogram. It is constructed by plotting the midpoints of the class intervals against the frequencies and joining the points with straight lines. Its purpose is to provide a smooth, continuous representation of the frequency distribution.
Advantages of Frequency Polygon: It is easier to compare two or more frequency distributions on the same graph, and it can be used for both grouped and ungrouped data.
5. What are the different parts of a table used for tabular presentation of data? Briefly explain the function of each part.
Answer: The different parts of a table are:
Table Number: A number assigned to the table for easy identification and reference.
Title: A concise and clear description of the table's content.
Headnote: A short note below the title to provide additional information, if needed.
Captions/Column Headings: The headings for the columns of the table.
Stubs/Row Headings: The headings for the rows of the table.
Body: The main part of the table containing the numerical data.
Footnote: A note at the bottom of the table to explain specific entries or abbreviations.
Source Note: A note at the bottom indicating the source from which the data was collected.
