FreeStatistics.org

Free Statistics

of Irreproducible Research!

Description of Statistical Computation

Author's title

Author*Unverified author*
R Software Modulerwasp_hypothesisvariance4.wasp
Title produced by softwareTesting Variance - Confidence Intervals for Population Variance
Date of computationThu, 13 Nov 2008 01:56:53 -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/t1226566704drllrg5khqzr5qy.htm/, Retrieved Sun, 19 May 2024 09:02:17 +0000
Statistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?pk=24492, Retrieved Sun, 19 May 2024 09:02:17 +0000
QR Codes:

Original text written by user:
IsPrivate?No (this computation is public)
User-defined keywordsjulie govaerts pork quality test
Estimated Impact194

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] [Testing Variance ...] [2008-11-13 08:56:53] [ff1af8c6f1c2f1c0e8def9bfc9355be9] [Current]
Feedback Forum
2008-11-16 19:58:32 [Annemiek Hoofman] [reply] 
Hiervoor moet je de module 'Testing Population Mean with known Variance' gebruiken. Het percentage van varkensvet mag niet meer dan 15% bedragen. Het steekproefgemiddelde is kleiner dan 0.1892 en ligt dus binnen het betrouwbaarheidsinterval.
2008-11-17 09:16:17 [Ken Wright] [reply] 
je hebt verkeerde module gebruikt, een juiste link:http://www.freestatistics.org/blog/index.php?v=date/2008/Nov/12/t1226486512ziliq66rc0x67ar.htm

hier moet je kijken dat 0.1546 onder de right tailed confidence interval ligt. We nemen hier de rechter omdat hier de leverancier alleen met veel vet een economisch voordeel kan halen.
2008-11-18 14:08:17 [Julie Govaerts] [reply] 
We gebruiken de one-sided confidence interval van de right-tail, omdat enkel de afwijking van het vetpercentage naar boven toe een economisch voordeel voor de producent kan betekenen
2008-11-18 17:27:37 [72e979bcc364082694890d2eccc1a66f] [reply] 
Hiervoor moet gebruik gemaakt worden van Testing mean with known variance - Confidence interval.
Hiervan moet je dan de rechterkant van de 1-sided test gebruiken omdat enkel een afwijking naar boven kan leiden tot een economisch voordeel.
Je komt dan tot de conclusie dat 15,46% nog onder de grens ligt, 18,9%.
2008-11-23 15:44:26 [Hannes Van Hoof] [reply] 
Je hebt de foute module gebruikt. de juiste was: Testing Population Mean with known Variance- confidence interval

Hierbij moet je de right one-sided confidence intervan gebruiken omdat enkel hier de producent voordeel kan halen. De 15,46 ligt onder de 0.1893 en dus binen de 95 % confidence interval.
2008-11-23 22:54:23 [Anouk Greeve] [reply] 
Je hebt inderdaad de verkeerde module gebruikt; de juiste is de module 'Testing Population Mean with known Variance'. We gebruiken de one-sided confidence interval van de right-tail (nauwkeuriger) omdat enkel de afwijking van het vetpercentage naar boven toe een economisch voordeel voor de producent kan betekenen.

Post a new message

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'Gwilym Jenkins' @ 72.249.127.135

\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 & 'Gwilym Jenkins' @ 72.249.127.135 \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=24492&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]'Gwilym Jenkins' @ 72.249.127.135[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=24492&T=0

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=24492&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'Gwilym Jenkins' @ 72.249.127.135






Testing Variance - Confidence Intervals for Population Variance
Sample size27
Sample variance0.012
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.950.007442185294740750.0225369937460200
Left one-sided confidence interval at 0.950.00802363089738211+inf
Right one-sided confidence interval at 0.9500.0202871983460766
more information about confidence interval

\begin{tabular}{lllllllll}
\hline
Testing Variance - Confidence Intervals for Population Variance \tabularnewline
Sample size & 27 \tabularnewline
Sample variance & 0.012 \tabularnewline
Confidence interval & 0.95 \tabularnewline
Type of Interval & Left tail & Right tail \tabularnewline
Two-sided confidence interval at  0.95 & 0.00744218529474075 & 0.0225369937460200 \tabularnewline
Left one-sided confidence interval at  0.95 & 0.00802363089738211 & +inf \tabularnewline
Right one-sided confidence interval at  0.95 & 0 & 0.0202871983460766 \tabularnewline
more information about confidence interval \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=24492&T=1

[TABLE]
[ROW][C]Testing Variance - Confidence Intervals for Population Variance[/C][/ROW]
[ROW][C]Sample size[/C][C]27[/C][/ROW]
[ROW][C]Sample variance[/C][C]0.012[/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]0.00744218529474075[/C][C]0.0225369937460200[/C][/ROW]
[ROW][C]Left one-sided confidence interval at  0.95[/C][C]0.00802363089738211[/C][C]+inf[/C][/ROW]
[ROW][C]Right one-sided confidence interval at  0.95[/C][C]0[/C][C]0.0202871983460766[/C][/ROW]
[ROW][C]more information about confidence interval[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=24492&T=1

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=24492&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 size27
Sample variance0.012
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.950.007442185294740750.0225369937460200
Left one-sided confidence interval at 0.950.00802363089738211+inf
Right one-sided confidence interval at 0.9500.0202871983460766
more information about confidence interval


Figures (Output of Computation)

Input Parameters & R Code

Parameters (Session):
par1 = 27 ; par2 = 0.012 ; par3 = 0.95 ;
Parameters (R input):
par1 = 27 ; par2 = 0.012 ; 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')