All exercise questions (and the in-text question asked within the chapter) from the NCERT textbook Practical Work in Geography Part II, Chapter 1, “Data – Its Source and Compilation”, exactly as the English edition prints them, with a full model answer for each. Try your own answer first, then check it against this one.
1 Choose the right answer from the four alternatives given below
Q. A number or character which represents measurement is called
(a) Digit (b) Data (c) Number (d) Character
Answer: (b) Data. The chapter defines data as numbers that represent measurements from the real world.
Q. A single datum is a single measurement from the
(a) Table (b) Frequency (c) Real world (d) Information
Answer: (c) Real world. The chapter states: “Datum is a single measurement” of the numbers that represent measurements from the real world.
Q. In a tally mark grouping by four and crossing fifth is called
(a) Four and Cross Method (b) Tally Marking Method (c) Frequency plotting Method (d) Inclusive Method
Answer: (a) Four and Cross Method. The chapter states raw data is classified “by a method popularly known as Four and Cross Method or tally marks.”
Q. An Ogive is a method in which
(a) Simple frequency is measured (b) Cumulative frequency is measured (c) Simple frequency is plotted (d) Cumulative frequency is plotted
Answer: (d) Cumulative frequency is plotted. The chapter states: “The curve obtained by plotting cumulative frequencies is called an Ogive.”
Q. If both ends of a group are taken in frequency grouping, it is called
(a) Exclusive Method (b) Inclusive Method (c) Marking Method (d) Statistical Method
Answer: (b) Inclusive Method. The chapter states that in the inclusive method, “both the upper and lower limit are included to find the frequency distribution.”
2 Answer the following questions in about 30 words
Q. Differentiate between data and information.
Answer: Data are raw numbers representing real-world measurements, which may be difficult to draw conclusions from in their unprocessed form. Information is what results after data are processed: a meaningful answer to a query, or a meaningful stimulus leading to further queries.
Q. What do you mean by data processing?
Answer: Data processing means tabulating and classifying raw data (which otherwise appears as a jumble of information) into a systematic form, such as a statistical table or a grouped frequency distribution, so that meaningful inferences can be drawn from it.
Q. What is the advantage of foot note in a table?
Answer: A footnote in a table explains or qualifies specific entries that need clarification, for example, Table 1.1’s footnotes clarify that the Jammu and Kashmir figure excludes PoK and that Chandigarh is a Union Territory, so the table’s figures are not misread.
Q. What do you mean by primary sources of data?
Answer: Primary sources of data are data collected for the first time by an individual, a group of individuals, or an institution/organisation, through Personal Observation, Interview, Questionnaire/Schedule, or Other Methods (e.g. soil or water quality kits).
Q. Enumerate five sources of secondary data.
Answer: Any five of: Government Publications, Semi/Quasi-government Publications, International Publications, Private Publications, Newspapers and Magazines, Electronic Media (published); or Government Documents, Quasi-government Records, Private Documents (unpublished).
3 Answer the following questions in about 125 words
Q. Discuss the national and international agencies where from secondary data may be collected.
Answer: National agencies include government bodies that publish or maintain records: the Office of the Registrar General of India (Census of India), the National Sample Survey, the India Meteorological Department (Weather Reports), state governments (Statistical Abstracts), and periodical Commission reports, together with Semi/Quasi-government bodies such as Urban Development Authorities, Municipal Corporations and Zila Parishads, and unpublished records such as village-level revenue records kept by the patwari. International agencies are chiefly various agencies of the United Nations, namely UNESCO, UNDP, WHO and FAO, whose periodically published works include the Demographic Year Book, the Statistical Year Book and the Human Development Report. Private publications (yearbooks, surveys and research reports by newspapers and private organisations) and electronic media, especially the internet, add further secondary data from both national and international sources.
Q. What is the importance of an index number? Taking an example examine the process of calculating an index number and show the changes.
Answer: An index number is a statistical measure designed to show changes in a variable, or a group of related variables, with respect to time, geographic location or other characteristics; it is widely used in economics and business to compare economic conditions, prices and quantities across different periods, locations, industries, cities or countries. Its importance lies in reducing changes over time or place to a single comparable figure, with the base year (or base value) fixed at 100. Example (Table 1.3, iron ore production in India, simple aggregate method, base year 1970-71): production of 32.5 million tonnes in 1970-71 is the base year and is set to index 100. Applying the formula (Σq1 ÷ Σq0) × 100 to later years: 1980-81’s 42.2 million tonnes gives an index of 130; 1990-91’s 53.7 million tonnes gives 165; and 2000-01’s 67.4 million tonnes gives 207. These changing index numbers show that iron ore production more than doubled between 1970-71 and 2000-01, a change that is far easier to read from the index series (100 → 130 → 165 → 207) than from the raw tonnage figures alone.
Q. In a class of 35 students of Geography, the following marks were obtained out of 10 marks in a unit test: 1, 0, 2, 3, 4, 5, 6, 7, 2, 3, 4, 0, 2, 5, 8, 4, 5, 3, 6, 3, 2, 7, 6, 5, 4, 3, 7, 8, 9, 7, 9, 4, 5, 4, 3. Represent the data in the form of a group frequency distribution.
Answer: Using the chapter’s own exclusive method, with a class interval of 2 marks:
| Marks (Group) | Tally | Frequency (f) |
|---|---|---|
| 0-2 | values 0, 1 | 3 |
| 2-4 | values 2, 3 | 10 |
| 4-6 | values 4, 5 | 11 |
| 6-8 | values 6, 7 | 7 |
| 8-10 | values 8, 9 | 4 |
| Total | Σf = N = 35 |
(A different, equally valid class interval, such as 3 marks per group, would give a different but equally correct grouping; the chapter itself leaves this choice to the student, as it does with Table 1.4’s grouping into ten classes.)
The book’s own second activity asks students to collect the last Geography test result of their own class and represent it as a group frequency distribution. This is a personal/field task with no single “correct” data set fixed by the chapter itself, so it is not turned into a written exam question here; the underlying method (finding the range, deciding classes and interval, tallying, and preparing the frequency table) is the same one demonstrated in Activity 1 above and in the chapter’s own Tables 1.4 to 1.6.
4 In-text question (asked within the chapter)
Q. You may now make out where all the marginal values of Table 1.4 will go.
Answer: The marginal values are the scores in Table 1.4 that are exactly equal to a class limit: 10, 50, 70, 80 and 90 (twice). In the exclusive method a value equal to a class limit is included in the group where it is the lower limit and excluded from the group where it is the upper limit. So 10 goes to 10-20 (not 0-10), 50 goes to 50-60 (not 40-50), 70 goes to 70-80, 80 goes to 80-90, and both 90s go to 90-100. This is exactly how they are placed in Table 1.5.
Q1(ii) is the exercise most likely to trip a student: it asks what a “datum” is a measurement from, not what a datum is: the answer is “the real world” (option c), not “a table” or “frequency”. Q1(v) is also easy to invert: “both ends taken” is the INCLUSIVE method, while the method that excludes the shared upper limit is the exclusive method. Learn the two side by side, from Table 1.6 (exclusive: 20-30, 30-40) and Table 1.7 (inclusive: 0-9, 10-19).