Mean Deviation
Chapter Name : Statistics |
Sub Topic Code : 104_11_15_04_04 |
Topic Name : Mean Deviation |
|
Sub Topic Name : Limitation Of Mean Deviation |
|
Introduction
• Statistics deals with data collected for specific purposes. • In order to have better data interpretation we should know how data is scattered and this measure is known as Measure of Dispersion. • Mean deviation of data is a measure of dispersion and it shows the amount of deviation that occurs around mean score of data but it has few limitations.
Pre-Requisites:
• Knowledge of representing data graphically and in tabular form. • Knowledge of measure of dispersion. • Knowledge of mean deviation.
Activity:
You will observe not ignoring signs make net sum of deviations 0.
Real Life Question:
In a quiz competition, scores of two teams are as given Team A : 3 2 3 -2 2 -3 -2 -3 Team B: 3 1 3 1 -3 -1 -3 -1 Find the mean deviation and its limitation.
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Statistics | Statistics is a method of gathering, analyzing and making conclusions from data. |
| Mean deviation | Mean deviation of data is the average distance between each data value and mean. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Scores of (positive and negative) quiz competition. | If you find out mean deviation there is need to ignore negative signs. Why? |
Real life uses :
Mean deviation of grouped is helpful in data analysis and data interpretation.
Practical examples around us
| Examples | Explainations |
|---|---|
| Stock exchange prices. | Suppose stock exchange prices are in fractions. Calculating mean deviation is difficult. One of the limitations of mean deviation is: if average is in fractions then it is difficult to calculate mean deviation. |
What you learn in Theory:
One of the limitations of mean deviation is algebraic treatment is absent.
What you learn in Practice:
If mean deviation of both data sets is same then we cannot have better data interpretation.