Chap 2 Frequency Distribution

8/20/2019 Chap 2 Frequency Distribution

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Topic 2 : FrequencyDistribution

Associate Professor Dr. Zaleha Binti IsmailSiti Nurashiken Binti Md. Sabudin

Statistic for EducationalResearch

MPU1!"


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Regular frequency distributionGrouped FrequencyDistributions

HistogramPolygons

InterpolationPercentile rank

Percentile


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Frequency Distributions

●Descriptive statistical techniques should be

performed by the researcher after collectingdata to organize the data in order to get ageneral picture of the results

● ! frequency distribution is a method fororganizing the data


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Frequency Distributions "#$●Frequency distribution is a summary of

data that sho%s frequency or numbersaccording to the scale of measurement● ! frequency distribution is the distributionof values that provide an overvie% of the

sample


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Frequency Distribution &ables●&he table has t%o columns'Column X represent list of categories on a scale

of measurement "($

● )olumn Y to represent the numbers of frequencyof each (

●&he sum of the frequencies should be equal to *+sample size


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Frequency Distribution &ables "#$

●,ther columns can be added-●&he third column represent the proportion "p$

for each category' p . f/* &he sum of the pcolumn must be equal to 011●&he fourth column represent percentage

distribution that correspond to each value of (&he percentage is obtained by multiplying p by011 &he total percentage is 011


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Regular Frequency Distribution

! regular frequency distribution table listall the ( values


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Grouped Frequency Distribution●2ometimes the set of score has a long listof ( values + so it should be simplified by

using a grouped frequency distribution table●In this table+ ( column called as classintervals+ not individual values

●)lass intervals should be in the samerange such as #+ 3+ 01 and etc


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Frequency Distribution Graphs

● ! frequency distribution graph have scorecategories "( values$ on the ( a4is and the

frequencies on the 5 a4is●&he shape of graph depend on the scorecategories● 6hen the scores are of an interval or ratio

scale+ the graph %ill be a histogram or apolygon


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Histograms

! histogram consists of tabularfrequencies+ sho%n as ad7acent rectangles+

erected %ith an area equal to the frequencyof the observations in the interval &heheight of a rectangle is also equal to thefrequency density of the interval &he totalarea of the histogram is equal to the numberof data


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1 2 ! " $

$

1

1$

2

2$

UPSR Result

Number of As

Frequency

( f

3 0#

8 01

9 #1

# 03

0 0#

00 : 08 03;0< #1;#8 #3;#< 91;98 93;9< 81;88

1

3

01

03

#1

#3

!ge of 2tudents in !=> ?ath )lass

!ge

* o o d

2 t u d e n t s

( f

81;88 8

93;9< @

91;98 01

#3;#< #1

#1;#8 03

03;0< 09

Histograms "#$


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Polygons

1 0 # 9 8 3 A B

1

3

01

03

#1

#3


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1 0 # 9 8 3 A B @ <

1

3

01

03

#1

#3

Polygons "#$


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=ar graphs

6hen the scores are measured nominal or

an ordinal scale+ the bar graph is used torepresent frequency distribution


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=ar graphs "#$

?athematics 2cience >nglish !rts

1

#

8

A

@

01

0#

2tudentsC Favourite 2ub7ect

2ub7ect

* o o f 2 t u d e n t s


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Relatif frequency is appropriate to dispalyfrequency distribution for large population

Relative frequency


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Relative frequency "#$

Graduated *on; Graduated

&eachersC Population

ualification

* o

o f t e a c h e r s

C 1 1 1


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2mooth curve

1 01 #1 91 81 31 33 A1 B1 @1


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2mooth curve

Symmetrical Distribution

Skewed Distribution


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Percentiles and Percentile Ranks+

and Interpolation●&he relative location of score can beidentified by percentiles and percentile

ranks●&he percentile rank for a score is thepercentage of individual %ith scores equal to

or less than the score●&he particular score is referred as apercentile


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)lass Frequency )umulative Frequency )umulative E

!rif 83 83 ##3E

=estari 81 @3 8#3E

)emerlang 9@ 0#9 A03E

Dinamik 81 0A9 @03E

>lit 9B #11 011E

Percentiles and Percentile Ranks+and Interpolation

What is the !th "ercentile#


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Percentiles and Percentile Ranks+and Interpolation "#$


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Percentiles and Percentile Ranks+and Interpolation

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Chap 2 Frequency Distribution