NCERT Class 12 Geography Practical Work in Geography Part II: Chapter 2 — Measures of Central Tendency
This chapter introduces students to the fundamental concepts of statistical analysis in Geography, focusing on Measures of Central Tendency. It explains that while organizing and presenting data makes them comprehensible, statistical techniques are crucial for analysis. The chapter highlights three main statistical techniques: Measures of Central Tendency, Measures of Dispersion, and Measures of Relationship. It defines Measures of Central Tendency as statistical techniques used to find the centre of data distributions, providing a single representative value. Key measures discussed include the mean, median, and mode. The chapter details how to calculate the mean for ungrouped data using the direct method, providing a formula and an example related to rainfall data. This foundational knowledge is essential for understanding geographical patterns and variations.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 12 |
| Subject | Geography |
| Book | Practical Work in Geography Part II |
| Chapter | Chapter 2 — Measures of Central Tendency |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 1 minute |
| Word count | 197 |
Learning outcomes
- Understand the importance of statistical techniques in data analysis.
- Define and differentiate between measures of central tendency, dispersion, and relationship.
- Identify the mean, median, and mode as key measures of central tendency.
- Learn the formula and method for calculating the mean from ungrouped data using the direct method.
- Appreciate the role of central tendency in representing geographical data.
Vocabulary
| Word | Meaning |
|---|---|
| Measures of Central Tendency | Statistical techniques used to find the centre of data distributions. |
| Measures of Dispersion | Statistical techniques that consider the internal variations of data around a central tendency. |
| Measures of Relationship | Statistical techniques that show the degree of association between two or more phenomena. |
| Mean | The arithmetic average of a set of values, calculated by summing all values and dividing by the number of observations. |
| Median | The middle value in a dataset when arranged in ascending or descending order, dividing the data into two equal halves. |
| Mode | The value that occurs most frequently in a dataset. |
| Ungrouped Data | Raw data that has not been classified or summarized into groups. |
| Direct Method | A method for calculating the mean by directly summing the values and dividing by the count. |
| Deviation | The difference between a data point and an assumed mean. |
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Practice questions
- What are the three main statistical techniques mentioned in the chapter? Answer: Measures of Central Tendency, Measures of Dispersion, and Measures of Relationship.
- Define the mean. Answer: The mean is the value derived by summing all the values in a dataset and dividing it by the number of observations.
- How is the median calculated for an even number of observations? Answer: For an even number of observations, the median is the average of the two middle-ranking values after arranging the data.
- What does the mode represent in a dataset? Answer: The mode represents the value that occurs with the maximum frequency at a particular point or value.
- What is the formula for calculating the mean from ungrouped data using the direct method? Answer: X = ∑x / N, where X is the mean, ∑x is the sum of all measures, and N is the number of measures.
Practice MCQs
Q1. Which statistical technique takes into account the internal variations of data around a central tendency?
Explanation: Measures of dispersion specifically focus on how spread out the data is, often in relation to a central point.
Q2. What is the primary function of Measures of Central Tendency?
Explanation: Measures of central tendency aim to find a single value that best represents the entire dataset.
Q3. Which of the following is NOT a measure of central tendency?
Explanation: Deviation is the difference from an assumed mean, not a measure of central tendency itself.
Q4. In the formula X = ∑x / N, what does 'N' represent?
Explanation: N in statistical formulas typically denotes the total count or number of data points in a set.
Q5. The median is the value that divides the arranged series into how many equal parts?
Explanation: The median is defined as the point that separates the higher half from the lower half of a data sample.
Frequently asked questions
What is the purpose of organizing and presenting data in Geography?
Organizing and presenting data makes them comprehensible and facilitates data processing for analysis.
What are the three main statistical techniques discussed in the chapter?
The three main techniques are Measures of Central Tendency, Measures of Dispersion, and Measures of Relationship.
What is the main goal of Measures of Central Tendency?
Their goal is to find a single value that best represents all the observations in a dataset, often lying near the centre of the distribution.
What are the common measures of central tendency?
The common measures of central tendency are the mean, median, and mode.
How is the mean calculated for ungrouped data using the direct method?
The mean is calculated by adding all the values (∑x) and dividing the sum by the total number of observations (N).
What is the difference between the mean and the median?
The mean is the arithmetic average, while the median is the middle value of an ordered dataset, making it less sensitive to extreme values.
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NCERT Class 12 Geography — Practical Work in Geography Part II — Chapter 2 — Measures of Central Tendency. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.