SlideShare a Scribd company logo
MEASURES OF
DISPERSIONS
MEASURES OF DISPERSIONS
• A quantity that measures the variability
among the data, or how the data one
dispersed about the average, known as
Measures of dispersion, scatter, or
variations.
• To know the average variation of different
values from the average of a series
• To know the range of values
• To compare between two or more series
expressed in different units
• To know whether the Central Tendency
truly represent the series or not
2. Common Measures of
Dispersion
• The main measures of dispersion
1. Range
2. Mean deviation or the average deviation
3. The variance & the standard deviation
5
The Range
• The range is defined as the difference
between the largest score in the set of
data and the smallest score in the set of
data, XL - XS
• What is the range of the following data:
4 8 1 6 6 2 9 3 6 9
• The largest score (XL) is 9; the smallest
score (XS) is 1; the range is XL - XS = 9 - 1 =
8
Ahad Kabir
1. RANGE
• Example:
1. Find the range in the following data.
31,26,15,43,19,10,12,37
Range = xm – xo 33 = 43 – 10
2. Find the range in the following F.D. (Ungrouped)
5 = 8 – 3
Range 5 = 8 – 3
3. Find the range in the following data.
Range = 60 – 10 = 50
X 3 4 5 6 7 8
f 5 8 12 10 4 2
X 10 - 20 20 - 30 30- 40 40 – 50 50 - 60
f 5 8 12 10 4
MEAN (OR AVERAGE) DEVIATION
• It is defined as the “Arithmetic mean of the
absolute deviation measured either from
the mean or median.
• or for ungroup.
• or for grouped.
n
xx
DM
∑ −
=..
N
xxf∑ −
=
N
medianx∑ −
N
medianxf∑ −
=
Example :
 
Sazzad took five exams in a class and had scores of 92, 75, 95, 90, 
and 98. Find the mean 
deviation for his test scores. 
 
     
          We can say that on the average, Saddam’s test scores deviated by 6 points from 
the mean.
Atik hasan
 
   
MEAN (OR AVERAGE) DEVIATION
• Exp: Calculate mean deviation from the FD (Grouped Data).
MD (x) =    33.6 / 20 = 1.68 
M.D = 23.72 / 14 = 1.69
X f Class Mark
( x )
f.x I x – 6.57 I f I x – 6.57 I
2 – 4 2 3 6 3.57 7.14
4 - 6 3 5 15 1.57 4.71
6 – 8 6 7 42 0.43 2.58
8 – 10 2 9 18 2.43 4.86
10 – 12 1 11 11 4.43 4.43
Total Σf =14 Σ f.x =92 Σ f I x – 6.57 I = 
23.72
=92/14=6.57ẋ
• It is an absolute measure.
• It’s relative measure is coefficient of M.D.
• Coefficient of M.D. = 
• It is based on all the observed values.
MEAN (OR AVERAGE) DEVIATION
median
DM
or
mean
DM ....
THE VARIANCE AND
STANDARD DEVIATION
• It is defined as “The mean of the squares 
of deviations of all the observation from 
their mean.” It’s square root is called 
“standard deviation”. 
• Usually it is denoted by    (for population of 
statistics)  S2
 (for sample) 
•   =    for ungrouped
2
σ
2
σ
n
xx∑ − 2
)(
Bakhtiare Hossain
 
   
•   =  for grouped
• It is an absolute measure;
• It is relative measure is coefficient of 
variation.
•  
• Shortcut method
N
xxf∑ − 2
)(2
σ
100. ×=
µ
σ
VC 100
..
.. ×=
x
DS
VC
22
2








−=
∑∑
N
x
N
x
σ
22
2
.








−=
∑∑
N
fx
N
xf
σ
THE VARIANCE AND
STANDARD DEVIATION
VARIANCE AND STANDARD
DEVIATION• Example:
1. Calculate  Variance and SD from the FD (Ungrouped Data).
Using Short cut method
var = (564 / 20) -    (98 /  20) ^ 2  =   28.2 – 24.01 = 4.09
Sd = √ σ^2 = √ 4.09 = 2.02
X f f.x X^2 f.x^2
2 3 6 4 12
4 9 36 16 144
6 5 30 36 180
8 2 16 64 128
10 1 10 100 100
Total Σf =20 Σf.x = 98 Σ f.x^2=564
22
2
.








−=
∑∑
N
fx
N
xf
σ
VARIANCE AND STANDARD
DEVIATION
• Exp: Calculate Variance and Standard deviation from the FD (Grouped Data).
Using Short cut method:
var = (670 /14) - (92 / 14) ^ 2 = 47.85 – 43.18 = 4.67
Sd = √ σ^2 = √ 4.67 = 2.16
X f Class Mark
( x )
f.x x^2 f.x^2
2 – 4 2 3 6 9 18
4 - 6 3 5 15 25 75
6 – 8 6 7 42 49 294
8 – 10 2 9 18 81 162
10 – 12 1 11 11 121 121
Total Σf =14 Σ f.x =92 Σ f.x^2 =670
22
2
.








−=
∑∑
N
fx
N
xf
σ
Imran hossain
Relative Measures ofRelative Measures of
DispersionDispersion
 Coefficient of Range
 Coefficient of Quartile Deviation
 Coefficient of Mean Deviation
 Coefficient of Variation (CV)
Relative Measures of VariationRelative Measures of Variation
Largest Smallest
Largest Smallest
Coefficient of Range
X X
X X
−
=
+
3 1
3 1
Coefficient of Quartile Deviation
Q Q
Q Q
−
=
+
Coefficient of Mean Deviation
MD
Mean
=
Coefficient of Variation (CV)Coefficient of Variation (CV)
Can be used to compare two or more
sets of data measured in different
units or same units but different
average size.
100%
X
S
CV ⋅







=
Use of Coefficient of VariationUse of Coefficient of Variation
Stock A:
Average price last year = $50
Standard deviation = $5
Stock B:
Average price last year = $100
Standard deviation = $5
but stock B is
less variable
relative to its
price
10%100%
$50
$5
100%
X
S
CVA =⋅=⋅







=
5%100%
$100
$5
100%
X
S
CVB =⋅=⋅







=
Both stocks
have the
same
standard
deviation
Arjun Baidya
Skewness
A fundamental task in many statistical analyses is to
characterize the location and variability of a data set
(Measures of central tendency vs. measures of dispersion)
Both measures tell us nothing about the shape of the
distribution
It is possible to have frequency distributions which differ
widely in their nature and composition and yet may have
same central tendency and dispersion.
Therefore, a further characterization of the data includes
skewness
Positive & Negative Skew
Positive skewness
There are more observations below the mean than
above it
When the mean is greater than the median
Negative skewness
There are a small number of low observations and a
large number of high ones
When the median is greater than the mean
Measures of Skew
Skew is a measure of symmetry in the distribution
of scores
Positive
Skew
Negative Skew
Normal
(skew = 0)
Measures of Skew
Robiul Sarkar
The Kurtosis is the degree of peakedness or flatness of a
unimodal (single humped) distribution,
• When the values of a variable are highly concentrated around
the mode, the peak of the curve becomes relatively high; the
curve is Leptokurtic.
• When the values of a variable have low concentration
around the mode, the peak of the curve becomes relatively
flat;curve is Platykurtic.
• A curve, which is neither very peaked nor very flat-toped, it
is taken as a basis for comparison, is called
Mesokurtic/Normal.
Measures of Kurtosis
Measures of Kurtosis
Measures of Kurtosis
1. If Coefficient of Kurtosis > 3 ----------------- Leptokurtic.
2. If Coefficient of Kurtosis = 3 ----------------- Mesokurtic.
3. If Coefficient of Kurtosis < 3 ----------------- is Platykurtic.
( )
( )
4
22
n X-X
Coefficient of Kurtosis=
X-X 
 
∑
∑

More Related Content

What's hot

Definition of dispersion
Definition of dispersionDefinition of dispersion
Definition of dispersion
Shah Alam Asim
 
MEAN DEVIATION VTU
MEAN DEVIATION VTUMEAN DEVIATION VTU
MEAN DEVIATION VTU
Sachin Somanna M P
 
VARIANCE
VARIANCEVARIANCE
Measures of central tendency and dispersion
Measures of central tendency and dispersionMeasures of central tendency and dispersion
Measures of central tendency and dispersion
Dr Dhavalkumar F. Chaudhary
 
Skewness & Kurtosis
Skewness & KurtosisSkewness & Kurtosis
Skewness & KurtosisNavin Bafna
 
Measures of dispersion
Measures of dispersionMeasures of dispersion
Measures of dispersion
Jagdish Powar
 
Measures of central tendancy
Measures of central tendancy Measures of central tendancy
Measures of central tendancy
Pranav Krishna
 
Measures of Variation or Dispersion
Measures of Variation or Dispersion Measures of Variation or Dispersion
Measures of Variation or Dispersion
Dr Athar Khan
 
Measures of central tendency ppt
Measures of central tendency pptMeasures of central tendency ppt
Measures of central tendency ppt
NighatKanwal
 
mean median mode
 mean median mode mean median mode
mean median mode
MITALI GUPTA
 
Measures of Dispersion
Measures of DispersionMeasures of Dispersion
Measures of Dispersion
Mohit Mahajan
 
Statistics-Measures of dispersions
Statistics-Measures of dispersionsStatistics-Measures of dispersions
Statistics-Measures of dispersionsCapricorn
 
Presentation on "Measure of central tendency"
Presentation on "Measure of central tendency"Presentation on "Measure of central tendency"
Presentation on "Measure of central tendency"
muhammad raza
 
Coefficient of variation
Coefficient of variationCoefficient of variation
Coefficient of variation
Nadeem Uddin
 
Measures of Variation
Measures of VariationMeasures of Variation
Measures of Variation
Rica Joy Pontilar
 
Variance and standard deviation
Variance and standard deviationVariance and standard deviation
Variance and standard deviationAmrit Swaroop
 
Skewness and kurtosis
Skewness and kurtosisSkewness and kurtosis
Skewness and kurtosis
KalimaniH
 

What's hot (20)

Definition of dispersion
Definition of dispersionDefinition of dispersion
Definition of dispersion
 
MEAN DEVIATION VTU
MEAN DEVIATION VTUMEAN DEVIATION VTU
MEAN DEVIATION VTU
 
VARIANCE
VARIANCEVARIANCE
VARIANCE
 
Central tendency
Central tendencyCentral tendency
Central tendency
 
Measures of central tendency and dispersion
Measures of central tendency and dispersionMeasures of central tendency and dispersion
Measures of central tendency and dispersion
 
Skewness & Kurtosis
Skewness & KurtosisSkewness & Kurtosis
Skewness & Kurtosis
 
Measures of dispersion
Measures of dispersionMeasures of dispersion
Measures of dispersion
 
Measures of central tendancy
Measures of central tendancy Measures of central tendancy
Measures of central tendancy
 
Measures of Variation or Dispersion
Measures of Variation or Dispersion Measures of Variation or Dispersion
Measures of Variation or Dispersion
 
Measures of central tendency ppt
Measures of central tendency pptMeasures of central tendency ppt
Measures of central tendency ppt
 
mean median mode
 mean median mode mean median mode
mean median mode
 
Measures of Dispersion
Measures of DispersionMeasures of Dispersion
Measures of Dispersion
 
Median
MedianMedian
Median
 
Statistics-Measures of dispersions
Statistics-Measures of dispersionsStatistics-Measures of dispersions
Statistics-Measures of dispersions
 
Presentation on "Measure of central tendency"
Presentation on "Measure of central tendency"Presentation on "Measure of central tendency"
Presentation on "Measure of central tendency"
 
Coefficient of variation
Coefficient of variationCoefficient of variation
Coefficient of variation
 
Mode
ModeMode
Mode
 
Measures of Variation
Measures of VariationMeasures of Variation
Measures of Variation
 
Variance and standard deviation
Variance and standard deviationVariance and standard deviation
Variance and standard deviation
 
Skewness and kurtosis
Skewness and kurtosisSkewness and kurtosis
Skewness and kurtosis
 

Similar to Measures of dispersions

Lecture. Introduction to Statistics (Measures of Dispersion).pptx
Lecture. Introduction to Statistics (Measures of Dispersion).pptxLecture. Introduction to Statistics (Measures of Dispersion).pptx
Lecture. Introduction to Statistics (Measures of Dispersion).pptx
NabeelAli89
 
State presentation2
State presentation2State presentation2
State presentation2
Lata Bhatta
 
ch-4-measures-of-variability-11 2.ppt for nursing
ch-4-measures-of-variability-11 2.ppt for nursingch-4-measures-of-variability-11 2.ppt for nursing
ch-4-measures-of-variability-11 2.ppt for nursing
windri3
 
measures-of-variability-11.ppt
measures-of-variability-11.pptmeasures-of-variability-11.ppt
measures-of-variability-11.ppt
NievesGuardian1
 
Unit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdf
Unit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdfUnit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdf
Unit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdf
Ravinandan A P
 
Measure of dispersion
Measure of dispersionMeasure of dispersion
Measure of dispersion
Waqar Abbasi
 
Absolute Measures of dispersion
Absolute Measures of dispersionAbsolute Measures of dispersion
Absolute Measures of dispersion
Ayushi Jain
 
Measures of Variability.pptx
Measures of Variability.pptxMeasures of Variability.pptx
Measures of Variability.pptx
NehaMishra52555
 
measure of variability (windri). In research include example
measure of variability (windri). In research include examplemeasure of variability (windri). In research include example
measure of variability (windri). In research include example
windri3
 
Measures of Dispersion .pptx
Measures of Dispersion .pptxMeasures of Dispersion .pptx
Measures of Dispersion .pptx
Vishal543707
 
Measures of Dispersion.pptx
Measures of Dispersion.pptxMeasures of Dispersion.pptx
Measures of Dispersion.pptx
Vanmala Buchke
 
Measures of dispersion
Measures of dispersionMeasures of dispersion
Measures of dispersion
Mayuri Joshi
 
Variability
VariabilityVariability
Business statistics
Business statisticsBusiness statistics
Business statistics
Ravi Prakash
 
Measures of Dispersion
Measures of DispersionMeasures of Dispersion
Measures of Dispersion
KainatIqbal7
 
Measure of dispersion by Neeraj Bhandari ( Surkhet.Nepal )
Measure of dispersion by Neeraj Bhandari ( Surkhet.Nepal )Measure of dispersion by Neeraj Bhandari ( Surkhet.Nepal )
Measure of dispersion by Neeraj Bhandari ( Surkhet.Nepal )Neeraj Bhandari
 
Statistics
StatisticsStatistics
Statistics
dineshmeena53
 
Measures of Variation.pdf
Measures of Variation.pdfMeasures of Variation.pdf
Measures of Variation.pdf
MuhammadFaizan389
 
Central tendency _dispersion
Central tendency _dispersionCentral tendency _dispersion
Central tendency _dispersion
Kirti Gupta
 

Similar to Measures of dispersions (20)

Lecture. Introduction to Statistics (Measures of Dispersion).pptx
Lecture. Introduction to Statistics (Measures of Dispersion).pptxLecture. Introduction to Statistics (Measures of Dispersion).pptx
Lecture. Introduction to Statistics (Measures of Dispersion).pptx
 
State presentation2
State presentation2State presentation2
State presentation2
 
ch-4-measures-of-variability-11 2.ppt for nursing
ch-4-measures-of-variability-11 2.ppt for nursingch-4-measures-of-variability-11 2.ppt for nursing
ch-4-measures-of-variability-11 2.ppt for nursing
 
measures-of-variability-11.ppt
measures-of-variability-11.pptmeasures-of-variability-11.ppt
measures-of-variability-11.ppt
 
Unit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdf
Unit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdfUnit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdf
Unit-I Measures of Dispersion- Biostatistics - Ravinandan A P.pdf
 
Measure of dispersion
Measure of dispersionMeasure of dispersion
Measure of dispersion
 
Absolute Measures of dispersion
Absolute Measures of dispersionAbsolute Measures of dispersion
Absolute Measures of dispersion
 
Measures of Variability.pptx
Measures of Variability.pptxMeasures of Variability.pptx
Measures of Variability.pptx
 
measure of variability (windri). In research include example
measure of variability (windri). In research include examplemeasure of variability (windri). In research include example
measure of variability (windri). In research include example
 
Measures of Dispersion .pptx
Measures of Dispersion .pptxMeasures of Dispersion .pptx
Measures of Dispersion .pptx
 
Measures of Dispersion.pptx
Measures of Dispersion.pptxMeasures of Dispersion.pptx
Measures of Dispersion.pptx
 
Measures of dispersion
Measures of dispersionMeasures of dispersion
Measures of dispersion
 
Variability
VariabilityVariability
Variability
 
Business statistics
Business statisticsBusiness statistics
Business statistics
 
Measures of Dispersion
Measures of DispersionMeasures of Dispersion
Measures of Dispersion
 
Measure of dispersion by Neeraj Bhandari ( Surkhet.Nepal )
Measure of dispersion by Neeraj Bhandari ( Surkhet.Nepal )Measure of dispersion by Neeraj Bhandari ( Surkhet.Nepal )
Measure of dispersion by Neeraj Bhandari ( Surkhet.Nepal )
 
Measures of dispersion
Measures  of  dispersionMeasures  of  dispersion
Measures of dispersion
 
Statistics
StatisticsStatistics
Statistics
 
Measures of Variation.pdf
Measures of Variation.pdfMeasures of Variation.pdf
Measures of Variation.pdf
 
Central tendency _dispersion
Central tendency _dispersionCentral tendency _dispersion
Central tendency _dispersion
 

More from Inamul Hossain Imran

Secondary storage.pptx
Secondary storage.pptxSecondary storage.pptx
Secondary storage.pptx
Inamul Hossain Imran
 
Region based segmentation
Region based segmentationRegion based segmentation
Region based segmentation
Inamul Hossain Imran
 
Thin film electroluminescent display
Thin film electroluminescent displayThin film electroluminescent display
Thin film electroluminescent display
Inamul Hossain Imran
 
CRT (Cathode ray tube)
CRT (Cathode ray tube)CRT (Cathode ray tube)
CRT (Cathode ray tube)
Inamul Hossain Imran
 
Color model
Color modelColor model
Computer graphics
Computer graphicsComputer graphics
Computer graphics
Inamul Hossain Imran
 
DDA (digital differential analyzer)
DDA (digital differential analyzer)DDA (digital differential analyzer)
DDA (digital differential analyzer)
Inamul Hossain Imran
 
Led (light emitting diode )
Led (light emitting diode )Led (light emitting diode )
Led (light emitting diode )
Inamul Hossain Imran
 
Virtual Blood Bank
Virtual Blood BankVirtual Blood Bank
Virtual Blood Bank
Inamul Hossain Imran
 
Compiler vs interpreter
Compiler vs interpreterCompiler vs interpreter
Compiler vs interpreter
Inamul Hossain Imran
 
Monopoly and monopolistic
Monopoly and monopolisticMonopoly and monopolistic
Monopoly and monopolistic
Inamul Hossain Imran
 
Monopolistic market
Monopolistic marketMonopolistic market
Monopolistic market
Inamul Hossain Imran
 
Oligopoly market
Oligopoly  marketOligopoly  market
Oligopoly market
Inamul Hossain Imran
 
Microeconomics vs macroeconomics
Microeconomics vs macroeconomicsMicroeconomics vs macroeconomics
Microeconomics vs macroeconomics
Inamul Hossain Imran
 
Cost and cost curve
Cost and cost curveCost and cost curve
Cost and cost curve
Inamul Hossain Imran
 
Historical Significance of Ahsan Manzil
Historical Significance of  Ahsan ManzilHistorical Significance of  Ahsan Manzil
Historical Significance of Ahsan Manzil
Inamul Hossain Imran
 
Sequential circuits
Sequential circuitsSequential circuits
Sequential circuits
Inamul Hossain Imran
 
Agriculture in bangladesh
Agriculture in bangladeshAgriculture in bangladesh
Agriculture in bangladesh
Inamul Hossain Imran
 
Properties of relations
Properties of relationsProperties of relations
Properties of relations
Inamul Hossain Imran
 
Graph and tree
Graph and treeGraph and tree
Graph and tree
Inamul Hossain Imran
 

More from Inamul Hossain Imran (20)

Secondary storage.pptx
Secondary storage.pptxSecondary storage.pptx
Secondary storage.pptx
 
Region based segmentation
Region based segmentationRegion based segmentation
Region based segmentation
 
Thin film electroluminescent display
Thin film electroluminescent displayThin film electroluminescent display
Thin film electroluminescent display
 
CRT (Cathode ray tube)
CRT (Cathode ray tube)CRT (Cathode ray tube)
CRT (Cathode ray tube)
 
Color model
Color modelColor model
Color model
 
Computer graphics
Computer graphicsComputer graphics
Computer graphics
 
DDA (digital differential analyzer)
DDA (digital differential analyzer)DDA (digital differential analyzer)
DDA (digital differential analyzer)
 
Led (light emitting diode )
Led (light emitting diode )Led (light emitting diode )
Led (light emitting diode )
 
Virtual Blood Bank
Virtual Blood BankVirtual Blood Bank
Virtual Blood Bank
 
Compiler vs interpreter
Compiler vs interpreterCompiler vs interpreter
Compiler vs interpreter
 
Monopoly and monopolistic
Monopoly and monopolisticMonopoly and monopolistic
Monopoly and monopolistic
 
Monopolistic market
Monopolistic marketMonopolistic market
Monopolistic market
 
Oligopoly market
Oligopoly  marketOligopoly  market
Oligopoly market
 
Microeconomics vs macroeconomics
Microeconomics vs macroeconomicsMicroeconomics vs macroeconomics
Microeconomics vs macroeconomics
 
Cost and cost curve
Cost and cost curveCost and cost curve
Cost and cost curve
 
Historical Significance of Ahsan Manzil
Historical Significance of  Ahsan ManzilHistorical Significance of  Ahsan Manzil
Historical Significance of Ahsan Manzil
 
Sequential circuits
Sequential circuitsSequential circuits
Sequential circuits
 
Agriculture in bangladesh
Agriculture in bangladeshAgriculture in bangladesh
Agriculture in bangladesh
 
Properties of relations
Properties of relationsProperties of relations
Properties of relations
 
Graph and tree
Graph and treeGraph and tree
Graph and tree
 

Recently uploaded

Polish students' mobility in the Czech Republic
Polish students' mobility in the Czech RepublicPolish students' mobility in the Czech Republic
Polish students' mobility in the Czech Republic
Anna Sz.
 
Palestine last event orientationfvgnh .pptx
Palestine last event orientationfvgnh .pptxPalestine last event orientationfvgnh .pptx
Palestine last event orientationfvgnh .pptx
RaedMohamed3
 
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
MysoreMuleSoftMeetup
 
Synthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptxSynthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptx
Pavel ( NSTU)
 
Instructions for Submissions thorugh G- Classroom.pptx
Instructions for Submissions thorugh G- Classroom.pptxInstructions for Submissions thorugh G- Classroom.pptx
Instructions for Submissions thorugh G- Classroom.pptx
Jheel Barad
 
Adversarial Attention Modeling for Multi-dimensional Emotion Regression.pdf
Adversarial Attention Modeling for Multi-dimensional Emotion Regression.pdfAdversarial Attention Modeling for Multi-dimensional Emotion Regression.pdf
Adversarial Attention Modeling for Multi-dimensional Emotion Regression.pdf
Po-Chuan Chen
 
The basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptxThe basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptx
heathfieldcps1
 
TESDA TM1 REVIEWER FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...
TESDA TM1 REVIEWER  FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...TESDA TM1 REVIEWER  FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...
TESDA TM1 REVIEWER FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...
EugeneSaldivar
 
The Challenger.pdf DNHS Official Publication
The Challenger.pdf DNHS Official PublicationThe Challenger.pdf DNHS Official Publication
The Challenger.pdf DNHS Official Publication
Delapenabediema
 
The geography of Taylor Swift - some ideas
The geography of Taylor Swift - some ideasThe geography of Taylor Swift - some ideas
The geography of Taylor Swift - some ideas
GeoBlogs
 
2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...
Sandy Millin
 
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXXPhrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
MIRIAMSALINAS13
 
Overview on Edible Vaccine: Pros & Cons with Mechanism
Overview on Edible Vaccine: Pros & Cons with MechanismOverview on Edible Vaccine: Pros & Cons with Mechanism
Overview on Edible Vaccine: Pros & Cons with Mechanism
DeeptiGupta154
 
Unit 8 - Information and Communication Technology (Paper I).pdf
Unit 8 - Information and Communication Technology (Paper I).pdfUnit 8 - Information and Communication Technology (Paper I).pdf
Unit 8 - Information and Communication Technology (Paper I).pdf
Thiyagu K
 
Acetabularia Information For Class 9 .docx
Acetabularia Information For Class 9  .docxAcetabularia Information For Class 9  .docx
Acetabularia Information For Class 9 .docx
vaibhavrinwa19
 
How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17
Celine George
 
Thesis Statement for students diagnonsed withADHD.ppt
Thesis Statement for students diagnonsed withADHD.pptThesis Statement for students diagnonsed withADHD.ppt
Thesis Statement for students diagnonsed withADHD.ppt
EverAndrsGuerraGuerr
 
Supporting (UKRI) OA monographs at Salford.pptx
Supporting (UKRI) OA monographs at Salford.pptxSupporting (UKRI) OA monographs at Salford.pptx
Supporting (UKRI) OA monographs at Salford.pptx
Jisc
 
The Roman Empire A Historical Colossus.pdf
The Roman Empire A Historical Colossus.pdfThe Roman Empire A Historical Colossus.pdf
The Roman Empire A Historical Colossus.pdf
kaushalkr1407
 
Chapter 3 - Islamic Banking Products and Services.pptx
Chapter 3 - Islamic Banking Products and Services.pptxChapter 3 - Islamic Banking Products and Services.pptx
Chapter 3 - Islamic Banking Products and Services.pptx
Mohd Adib Abd Muin, Senior Lecturer at Universiti Utara Malaysia
 

Recently uploaded (20)

Polish students' mobility in the Czech Republic
Polish students' mobility in the Czech RepublicPolish students' mobility in the Czech Republic
Polish students' mobility in the Czech Republic
 
Palestine last event orientationfvgnh .pptx
Palestine last event orientationfvgnh .pptxPalestine last event orientationfvgnh .pptx
Palestine last event orientationfvgnh .pptx
 
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
Mule 4.6 & Java 17 Upgrade | MuleSoft Mysore Meetup #46
 
Synthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptxSynthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptx
 
Instructions for Submissions thorugh G- Classroom.pptx
Instructions for Submissions thorugh G- Classroom.pptxInstructions for Submissions thorugh G- Classroom.pptx
Instructions for Submissions thorugh G- Classroom.pptx
 
Adversarial Attention Modeling for Multi-dimensional Emotion Regression.pdf
Adversarial Attention Modeling for Multi-dimensional Emotion Regression.pdfAdversarial Attention Modeling for Multi-dimensional Emotion Regression.pdf
Adversarial Attention Modeling for Multi-dimensional Emotion Regression.pdf
 
The basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptxThe basics of sentences session 5pptx.pptx
The basics of sentences session 5pptx.pptx
 
TESDA TM1 REVIEWER FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...
TESDA TM1 REVIEWER  FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...TESDA TM1 REVIEWER  FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...
TESDA TM1 REVIEWER FOR NATIONAL ASSESSMENT WRITTEN AND ORAL QUESTIONS WITH A...
 
The Challenger.pdf DNHS Official Publication
The Challenger.pdf DNHS Official PublicationThe Challenger.pdf DNHS Official Publication
The Challenger.pdf DNHS Official Publication
 
The geography of Taylor Swift - some ideas
The geography of Taylor Swift - some ideasThe geography of Taylor Swift - some ideas
The geography of Taylor Swift - some ideas
 
2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...
 
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXXPhrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
 
Overview on Edible Vaccine: Pros & Cons with Mechanism
Overview on Edible Vaccine: Pros & Cons with MechanismOverview on Edible Vaccine: Pros & Cons with Mechanism
Overview on Edible Vaccine: Pros & Cons with Mechanism
 
Unit 8 - Information and Communication Technology (Paper I).pdf
Unit 8 - Information and Communication Technology (Paper I).pdfUnit 8 - Information and Communication Technology (Paper I).pdf
Unit 8 - Information and Communication Technology (Paper I).pdf
 
Acetabularia Information For Class 9 .docx
Acetabularia Information For Class 9  .docxAcetabularia Information For Class 9  .docx
Acetabularia Information For Class 9 .docx
 
How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17
 
Thesis Statement for students diagnonsed withADHD.ppt
Thesis Statement for students diagnonsed withADHD.pptThesis Statement for students diagnonsed withADHD.ppt
Thesis Statement for students diagnonsed withADHD.ppt
 
Supporting (UKRI) OA monographs at Salford.pptx
Supporting (UKRI) OA monographs at Salford.pptxSupporting (UKRI) OA monographs at Salford.pptx
Supporting (UKRI) OA monographs at Salford.pptx
 
The Roman Empire A Historical Colossus.pdf
The Roman Empire A Historical Colossus.pdfThe Roman Empire A Historical Colossus.pdf
The Roman Empire A Historical Colossus.pdf
 
Chapter 3 - Islamic Banking Products and Services.pptx
Chapter 3 - Islamic Banking Products and Services.pptxChapter 3 - Islamic Banking Products and Services.pptx
Chapter 3 - Islamic Banking Products and Services.pptx
 

Measures of dispersions

  • 2. MEASURES OF DISPERSIONS • A quantity that measures the variability among the data, or how the data one dispersed about the average, known as Measures of dispersion, scatter, or variations.
  • 3. • To know the average variation of different values from the average of a series • To know the range of values • To compare between two or more series expressed in different units • To know whether the Central Tendency truly represent the series or not
  • 4. 2. Common Measures of Dispersion • The main measures of dispersion 1. Range 2. Mean deviation or the average deviation 3. The variance & the standard deviation
  • 5. 5 The Range • The range is defined as the difference between the largest score in the set of data and the smallest score in the set of data, XL - XS • What is the range of the following data: 4 8 1 6 6 2 9 3 6 9 • The largest score (XL) is 9; the smallest score (XS) is 1; the range is XL - XS = 9 - 1 = 8
  • 7. 1. RANGE • Example: 1. Find the range in the following data. 31,26,15,43,19,10,12,37 Range = xm – xo 33 = 43 – 10 2. Find the range in the following F.D. (Ungrouped) 5 = 8 – 3 Range 5 = 8 – 3 3. Find the range in the following data. Range = 60 – 10 = 50 X 3 4 5 6 7 8 f 5 8 12 10 4 2 X 10 - 20 20 - 30 30- 40 40 – 50 50 - 60 f 5 8 12 10 4
  • 8. MEAN (OR AVERAGE) DEVIATION • It is defined as the “Arithmetic mean of the absolute deviation measured either from the mean or median. • or for ungroup. • or for grouped. n xx DM ∑ − =.. N xxf∑ − = N medianx∑ − N medianxf∑ − =
  • 11. MEAN (OR AVERAGE) DEVIATION • Exp: Calculate mean deviation from the FD (Grouped Data). MD (x) =    33.6 / 20 = 1.68  M.D = 23.72 / 14 = 1.69 X f Class Mark ( x ) f.x I x – 6.57 I f I x – 6.57 I 2 – 4 2 3 6 3.57 7.14 4 - 6 3 5 15 1.57 4.71 6 – 8 6 7 42 0.43 2.58 8 – 10 2 9 18 2.43 4.86 10 – 12 1 11 11 4.43 4.43 Total Σf =14 Σ f.x =92 Σ f I x – 6.57 I =  23.72 =92/14=6.57ẋ
  • 12. • It is an absolute measure. • It’s relative measure is coefficient of M.D. • Coefficient of M.D. =  • It is based on all the observed values. MEAN (OR AVERAGE) DEVIATION median DM or mean DM ....
  • 13. THE VARIANCE AND STANDARD DEVIATION • It is defined as “The mean of the squares  of deviations of all the observation from  their mean.” It’s square root is called  “standard deviation”.  • Usually it is denoted by    (for population of  statistics)  S2  (for sample)  •   =    for ungrouped 2 σ 2 σ n xx∑ − 2 )(
  • 15. •   =  for grouped • It is an absolute measure; • It is relative measure is coefficient of  variation. •   • Shortcut method N xxf∑ − 2 )(2 σ 100. ×= µ σ VC 100 .. .. ×= x DS VC 22 2         −= ∑∑ N x N x σ 22 2 .         −= ∑∑ N fx N xf σ THE VARIANCE AND STANDARD DEVIATION
  • 16. VARIANCE AND STANDARD DEVIATION• Example: 1. Calculate  Variance and SD from the FD (Ungrouped Data). Using Short cut method var = (564 / 20) -    (98 /  20) ^ 2  =   28.2 – 24.01 = 4.09 Sd = √ σ^2 = √ 4.09 = 2.02 X f f.x X^2 f.x^2 2 3 6 4 12 4 9 36 16 144 6 5 30 36 180 8 2 16 64 128 10 1 10 100 100 Total Σf =20 Σf.x = 98 Σ f.x^2=564 22 2 .         −= ∑∑ N fx N xf σ
  • 17. VARIANCE AND STANDARD DEVIATION • Exp: Calculate Variance and Standard deviation from the FD (Grouped Data). Using Short cut method: var = (670 /14) - (92 / 14) ^ 2 = 47.85 – 43.18 = 4.67 Sd = √ σ^2 = √ 4.67 = 2.16 X f Class Mark ( x ) f.x x^2 f.x^2 2 – 4 2 3 6 9 18 4 - 6 3 5 15 25 75 6 – 8 6 7 42 49 294 8 – 10 2 9 18 81 162 10 – 12 1 11 11 121 121 Total Σf =14 Σ f.x =92 Σ f.x^2 =670 22 2 .         −= ∑∑ N fx N xf σ
  • 19. Relative Measures ofRelative Measures of DispersionDispersion  Coefficient of Range  Coefficient of Quartile Deviation  Coefficient of Mean Deviation  Coefficient of Variation (CV)
  • 20. Relative Measures of VariationRelative Measures of Variation Largest Smallest Largest Smallest Coefficient of Range X X X X − = + 3 1 3 1 Coefficient of Quartile Deviation Q Q Q Q − = + Coefficient of Mean Deviation MD Mean =
  • 21. Coefficient of Variation (CV)Coefficient of Variation (CV) Can be used to compare two or more sets of data measured in different units or same units but different average size. 100% X S CV ⋅        =
  • 22. Use of Coefficient of VariationUse of Coefficient of Variation Stock A: Average price last year = $50 Standard deviation = $5 Stock B: Average price last year = $100 Standard deviation = $5 but stock B is less variable relative to its price 10%100% $50 $5 100% X S CVA =⋅=⋅        = 5%100% $100 $5 100% X S CVB =⋅=⋅        = Both stocks have the same standard deviation
  • 24. Skewness A fundamental task in many statistical analyses is to characterize the location and variability of a data set (Measures of central tendency vs. measures of dispersion) Both measures tell us nothing about the shape of the distribution It is possible to have frequency distributions which differ widely in their nature and composition and yet may have same central tendency and dispersion. Therefore, a further characterization of the data includes skewness
  • 25. Positive & Negative Skew Positive skewness There are more observations below the mean than above it When the mean is greater than the median Negative skewness There are a small number of low observations and a large number of high ones When the median is greater than the mean
  • 26. Measures of Skew Skew is a measure of symmetry in the distribution of scores Positive Skew Negative Skew Normal (skew = 0)
  • 29. The Kurtosis is the degree of peakedness or flatness of a unimodal (single humped) distribution, • When the values of a variable are highly concentrated around the mode, the peak of the curve becomes relatively high; the curve is Leptokurtic. • When the values of a variable have low concentration around the mode, the peak of the curve becomes relatively flat;curve is Platykurtic. • A curve, which is neither very peaked nor very flat-toped, it is taken as a basis for comparison, is called Mesokurtic/Normal. Measures of Kurtosis
  • 31. Measures of Kurtosis 1. If Coefficient of Kurtosis > 3 ----------------- Leptokurtic. 2. If Coefficient of Kurtosis = 3 ----------------- Mesokurtic. 3. If Coefficient of Kurtosis < 3 ----------------- is Platykurtic. ( ) ( ) 4 22 n X-X Coefficient of Kurtosis= X-X    ∑ ∑