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Description of Statistical Computation

Author's title

Author*The author of this computation has been verified*
R Software Modulerwasp_hypothesisvariance4.wasp
Title produced by softwareTesting Variance - Confidence Intervals for Population Variance
Date of computationThu, 13 Nov 2008 02:11:37 -0700
Cite this page as followsStatistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?v=date/2008/Nov/13/t12265675535eqdfiyg8j06buh.htm/, Retrieved Mon, 20 May 2024 09:44:42 +0000
Statistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?pk=24502, Retrieved Mon, 20 May 2024 09:44:42 +0000
QR Codes:

Original text written by user:
IsPrivate?No (this computation is public)
User-defined keywords
Estimated Impact165

Tree of Dependent Computations

Family? (F = Feedback message, R = changed R code, M = changed R Module, P = changed Parameters, D = changed Data)
F       [Testing Variance - Confidence Intervals for Population Variance] [tinneke_debock.hy...] [2008-11-13 09:11:37] [20137734a2343a7bbbd59daaec7ad301] [Current]
Feedback Forum
2008-11-15 18:11:48 [Philip Van Herck] [reply] 
Het juiste antwoord is: De distributie van de variantie is niet symmetrisch en bijgevolg ook niet normaal verdeeld. Dit kunnen we stellen omdat de 95% confidence intervals van de steekproef niet symmetrisch zijn.
2008-11-24 17:56:09 [Marlies Polfliet] [reply] 
De student had hier de juiste berekeningen gemaakt, maar had daaruit geen conclusies getrokken. De distributie van de variantie is niet normaal verdeeld/ niet symmetrisch.
2008-11-24 21:44:50 [Jonas Scheltjens] [reply] 
Q4: Hier is het antwoord door de student niet gegeven. Het antwoord luidt dus neen, omdat de variantie steeds binnen het interval [0; +∞] ligt, en dit kan men ook besluiten aangezien wat men kan waarnemen bij de gegevens omtrent deze waarden (de linkse en rechtse externe delen van het betrouwbaarheidsinterval zijn niet even groot). Daarom kan men stellen dat de variantie niet symmetrisch en normaal verdeeld is.

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Dataset

Tables (Output of Computation)





Summary of computational transaction
Raw Inputview raw input (R code)
Raw Outputview raw output of R engine
Computing time1 seconds
R Server'George Udny Yule' @ 72.249.76.132

\begin{tabular}{lllllllll}
\hline
Summary of computational transaction \tabularnewline
Raw Input & view raw input (R code)  \tabularnewline
Raw Output & view raw output of R engine  \tabularnewline
Computing time & 1 seconds \tabularnewline
R Server & 'George Udny Yule' @ 72.249.76.132 \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=24502&T=0

[TABLE]
[ROW][C]Summary of computational transaction[/C][/ROW]
[ROW][C]Raw Input[/C][C]view raw input (R code) [/C][/ROW]
[ROW][C]Raw Output[/C][C]view raw output of R engine [/C][/ROW]
[ROW][C]Computing time[/C][C]1 seconds[/C][/ROW]
[ROW][C]R Server[/C][C]'George Udny Yule' @ 72.249.76.132[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=24502&T=0

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=24502&T=0

As an alternative you can also use a QR Code:  
QR Code


The GUIDs for individual cells are displayed in the table below:

Summary of computational transaction
Raw Inputview raw input (R code)
Raw Outputview raw output of R engine
Computing time1 seconds
R Server'George Udny Yule' @ 72.249.76.132






Testing Variance - Confidence Intervals for Population Variance
Sample size320
Sample variance4.2
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.953.617440959935954.93635971376001
Left one-sided confidence interval at 0.953.70466242131918+inf
Right one-sided confidence interval at 0.9504.80868448592078
more information about confidence interval

\begin{tabular}{lllllllll}
\hline
Testing Variance - Confidence Intervals for Population Variance \tabularnewline
Sample size & 320 \tabularnewline
Sample variance & 4.2 \tabularnewline
Confidence interval & 0.95 \tabularnewline
Type of Interval & Left tail & Right tail \tabularnewline
Two-sided confidence interval at  0.95 & 3.61744095993595 & 4.93635971376001 \tabularnewline
Left one-sided confidence interval at  0.95 & 3.70466242131918 & +inf \tabularnewline
Right one-sided confidence interval at  0.95 & 0 & 4.80868448592078 \tabularnewline
more information about confidence interval \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=24502&T=1

[TABLE]
[ROW][C]Testing Variance - Confidence Intervals for Population Variance[/C][/ROW]
[ROW][C]Sample size[/C][C]320[/C][/ROW]
[ROW][C]Sample variance[/C][C]4.2[/C][/ROW]
[ROW][C]Confidence interval[/C][C]0.95[/C][/ROW]
[ROW][C]Type of Interval[/C][C]Left tail[/C][C]Right tail[/C][/ROW]
[ROW][C]Two-sided confidence interval at  0.95[/C][C]3.61744095993595[/C][C]4.93635971376001[/C][/ROW]
[ROW][C]Left one-sided confidence interval at  0.95[/C][C]3.70466242131918[/C][C]+inf[/C][/ROW]
[ROW][C]Right one-sided confidence interval at  0.95[/C][C]0[/C][C]4.80868448592078[/C][/ROW]
[ROW][C]more information about confidence interval[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=24502&T=1

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=24502&T=1

As an alternative you can also use a QR Code:  
QR Code


The GUIDs for individual cells are displayed in the table below:

Testing Variance - Confidence Intervals for Population Variance
Sample size320
Sample variance4.2
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.953.617440959935954.93635971376001
Left one-sided confidence interval at 0.953.70466242131918+inf
Right one-sided confidence interval at 0.9504.80868448592078
more information about confidence interval


Figures (Output of Computation)

Input Parameters & R Code

Parameters (Session):
par1 = 320 ; par2 = 4.2 ; par3 = 0.95 ;
Parameters (R input):
par1 = 320 ; par2 = 4.2 ; par3 = 0.95 ;
R code (references can be found in the software module):
par1<-as.numeric(par1)
par2<-as.numeric(par2)
par3<-as.numeric(par3)
df <- par1 - 1
halfalpha <- (1 - par3) / 2
ub <- par2 * df / qchisq(halfalpha,df)
ua <- par2 * df / qchisq(1-halfalpha,df)
ua
ub
ur <- par2 * df / qchisq(1-par3,df)
ur
ul <- par2 * df / qchisq(par3,df)
ul
load(file='createtable')
a<-table.start()
a<-table.row.start(a)
a<-table.element(a,hyperlink('ht_variance.htm','Testing Variance - Confidence Intervals for Population Variance','learn more about Statistical Hypothesis Testing about the Variance'),3,TRUE)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Sample size',header=TRUE)
a<-table.element(a,par1,2)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Sample variance',header=TRUE)
a<-table.element(a,par2,2)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Confidence interval',header=TRUE)
a<-table.element(a,par3,2)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Type of Interval',header=TRUE)
a<-table.element(a,'Left tail',header=TRUE)
a<-table.element(a,'Right tail',header=TRUE)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,paste('Two-sided confidence interval at ',par3), header=TRUE)
a<-table.element(a,ua)
a<-table.element(a,ub)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,paste('Left one-sided confidence interval at ',par3), header=TRUE)
a<-table.element(a,ul)
a<-table.element(a,'+inf')
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,paste('Right one-sided confidence interval at ',par3), header=TRUE)
a<-table.element(a,'0')
a<-table.element(a,ur)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a, hyperlink('ht_variance.htm#ex4', 'more information about confidence interval','example'),3,TRUE)
a<-table.row.end(a)
a<-table.end(a)
table.save(a,file='mytable.tab')