NCERT Class 11 Economics Chapter 5: Measures of Central Tendency PDF Download

Chapter 5 of Class 11 Economics, Measures of Central Tendency, is all about finding a single value that represents the entire dataset. It explains how to calculate the average or typical value from a group of numbers. This chapter introduces three main measures – Mean, Median, and Mode. These are basic tools used to summarise

Chapter 5 of Class 11 Economics, Measures of Central Tendency, is all about finding a single value that represents the entire dataset. It explains how to calculate the average or typical value from a group of numbers. This chapter introduces three main measures – Mean, Median, and Mode. These are basic tools used to summarise and understand data. Whether it’s marks of students, income of households, or rainfall records, central tendency helps to give a quick idea of the general pattern.

I’m writing about this chapter because it forms the base for understanding data analysis in economics. Without knowing how to calculate the average or central value, it’s difficult to study patterns, compare data or make economic decisions. This chapter is important not just for exams but also in real life where averages are used everywhere – from news reports to finance. Students often get confused between different types of averages, so having clear examples and a downloadable PDF can help a lot during revision and practice.

Understanding Measures of Central Tendency

Measures of central tendency are values that represent the middle or central part of a data set. They help in summarising large sets of numbers into a single, easy-to-understand figure.

The Three Main Measures

1. Mean (Arithmetic Average)

Add all values and divide by the number of observations
Best used when there are no extreme values
Example: If marks in a class are 50, 60, 70, then Mean = (50+60+70)/3 = 60

2. Median (Middle Value)

The middle number when data is arranged in order
Best when data is skewed or has outliers
Example: If data is 45, 50, 55, the median is 50

3. Mode (Most Frequent Value)

The number that appears most often in a dataset
Useful for finding the most common item
Example: In 5, 6, 6, 6, 7 – Mode is 6

When to Use Which

Use Mean for balanced data
Use Median when data has outliers
Use Mode when you need the most common figure

Formulas and Types of Data

This chapter also explains how to calculate these values for different types of data:

Ungrouped Data – Raw numbers
Discrete Series – Data with separate values
Frequency Distribution – Data grouped into intervals

It gives step-by-step methods and also short-cuts like the Assumed Mean method to make long calculations easier.

Here’s a simple example table:

Marks Range	Frequency
10–20	5
20–30	8
30–40	12

From such a table, you can calculate Mean using assumed mean or step deviation method as shown in the NCERT book.

Why This Chapter Matters in Real Life

Averages are used in calculating GDP, inflation, and literacy rates
Helps in summarising data in business reports
Used in market research, surveys, and policymaking
Common in competitive exams and entrance tests

For example, when the government reports “average income of Indians increased”, it’s mostly based on one of these central tendency measures.

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Click Here to Download NCERT Class 11 Economics Chapter 5: Measures of Central Tendency PDF

NCERT Class 12 Sociology Part 2 Chapter 8: Social Movements PDF Download

Social movements have always been a powerful force for change in society, and NCERT Class 12 Sociology Part 2 Chapter 8 focuses on understanding their forms, causes, and impact. The chapter explains how movements arise, the role of leadership, and how they influence both policies and public opinion. It also discusses the differences between social

I am writing about this topic because students often find it difficult to connect textbook theory with real-life events. This chapter is important as it gives clarity on why social movements occur, how they are sustained, and how they shape society in the long run. Understanding this is not only essential for exam preparation but also for developing awareness as responsible citizens. For instance, movements like the Chipko Movement, Civil Rights Movement, or farmers’ protests are rooted in the same principles discussed in this chapter. By studying this topic, students can relate classroom learning to the real world and also develop critical thinking on social change.

Overview of Social Movements in Sociology

In sociology, social movements are defined as organised efforts by a large group of people to bring about or resist change in society. The chapter categorises movements into different types:

Reformist movements – Aim to change specific laws or policies without altering the entire system.
Revolutionary movements – Seek to completely change the political, social, or economic order.
Reactionary movements – Work towards resisting or reversing changes in society.
Redemptive movements – Focus on changing individuals’ lives rather than structural changes.

The NCERT text also explains that social movements have four main stages – emergence, coalescence, bureaucratisation, and decline. Examples like the Dalit movement, women’s rights movements, and environmental movements help students understand these concepts better.

Key Features Discussed in the Chapter

Movements can be short-term or long-term depending on their goals and public support.
Leadership and organisation play a big role in sustaining the movement.
Media often acts as a catalyst by spreading awareness and gathering public opinion.
Social movements are different from riots or spontaneous protests because they have a clear objective and planned strategies.

Why This Chapter is Relevant for Students

Understanding social movements helps students not only in sociology but also in subjects like political science, history, and current affairs. It strengthens analytical skills and helps in competitive exams like UPSC, where social change is a key theme.

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Students who want to read the full chapter can download the official NCERT Class 12 Sociology Part 2 Chapter 8: Social Movements PDF from this website:

NCERT Class 12 Sociology Part 2 Chapter 8: Social Movements