# Measures Of Dispersion

## Overview

Measures of Dispersion in statistics play a crucial role in providing insights into the spread or variability of a dataset. In this course material, we will delve into understanding and calculating various measures of dispersion such as range, mean deviation, variance, and standard deviation for ungrouped and grouped data.

Range is the simplest measure of dispersion, defined as the difference between the highest and lowest values in the dataset. It gives a quick overview of how spread out the data points are. Calculating the range involves subtracting the minimum value from the maximum value.

Next, we will explore Mean Deviation, which measures the average distance of each data point from the mean. It provides information on the variability around the mean without considering the direction of deviations. Mean deviation is computed by finding the average of the absolute differences between each data point and the mean.

Moving on to Variance, this measure quantifies the spread of data points around the mean. It takes into account the squared differences between each data point and the mean, providing a more comprehensive understanding of dispersion. Variance is calculated by finding the average of the squared deviations from the mean.

Finally, we will explore Standard Deviation, which is the square root of the variance. Standard deviation is a widely used measure of dispersion that indicates the extent to which data points deviate from the mean. It provides a measure of the typical distance between each data point and the mean, offering valuable insights into the variability of the dataset.

Through this course material, you will learn how to calculate these measures of dispersion for both ungrouped and grouped data. Understanding these concepts is essential in analyzing data and making informed decisions based on the variability present in the dataset.

Prepare to enhance your statistical skills as we delve into the comprehensive calculation and interpretation of range, mean deviation, variance, and standard deviation for ungrouped and grouped data.

## Objectives

1. Understand the Concept of Dispersion in Statistics
2. Calculate the Variance
3. Calculate the Range
4. Calculate the Measures of Dispersion for Ungrouped Data
5. Calculate the Mean Deviation
6. Calculate the Standard Deviation
7. Calculate the Measures of Dispersion for Grouped Data

## Lesson Note

Measures of dispersion are statistical tools used to describe the distribution and spread of data points in a dataset. While measures of central tendency (like mean, median, and mode) provide a central value for the data, measures of dispersion give us an idea of how much the data varies from this central value.

## Lesson Evaluation

Congratulations on completing the lesson on Measures Of Dispersion. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

1. Calculate the range of the following data: 13, 17, 22, 25, 29 A. 12 B. 16 C. 17 D. 29 Answer: A. 16
2. Find the mean deviation of the data set: 4, 9, 13, 18, 25 A. 8 B. 6.2 C. 3.6 D. 2.8 Answer: D. 2.8
3. Given the following data set: 7, 12, 16, 21, 27, find the variance. A. 45 B. 64 C. 70 D. 54 Answer: D. 54
4. Calculate the standard deviation of the data set: 8, 12, 16, 20, 24 A. 4 B. 5 C. 6 D. 8 Answer: B. 5
5. For the following data set: 5, 8, 12, 16, 19, find the range. A. 14 B. 15 C. 17 D. 19 Answer: B. 15
6. What is the mean deviation of the data set: 7, 10, 14, 18, 21? A. 6 B. 5 C. 3 D. 2 Answer: C. 3
7. Calculate the variance of the data set: 3, 6, 10, 14, 18 A. 23 B. 16 C. 12 D. 8 Answer: B. 16
8. Determine the standard deviation of the given data set: 12, 17, 22, 27, 32 A. 5 B. 6 C. 7 D. 8 Answer: A. 5
9. Find the range of the following data: 9, 14, 20, 25, 28 A. 19 B. 20 C. 19.6 D. 18 Answer: D. 18

## Past Questions

Wondering what past questions for this topic looks like? Here are a number of questions about Measures Of Dispersion from previous years

Question 1

Find the volume of the composite solid above.

Question 1

Find the median of the distribution

Question 1

The ages of 10 students in a class are; 15, 16, 15.5, 17, 14.9, 14.5, 14.1, 15.1, 14.8. find the range of their ages.

Practice a number of Measures Of Dispersion past questions