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Description of Statistical Computation

Author's title

Author*Unverified author*
R Software Modulerwasp_hypothesisvariance3.wasp
Title produced by softwareTesting Variance - Confidence Intervals for Sample Variance
Date of computationThu, 13 Nov 2008 01:51:23 -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/t1226566480ygj8u409e0laa09.htm/, Retrieved Sun, 19 May 2024 00:28:02 +0000
Statistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?pk=24491, Retrieved Sun, 19 May 2024 00:28:02 +0000
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Original text written by user:
IsPrivate?No (this computation is public)
User-defined keywordsjulie govaerts pork quality test
Estimated Impact188

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 Sample Variance] [Testing Variance ...] [2008-11-13 08:51:23] [ff1af8c6f1c2f1c0e8def9bfc9355be9] [Current]
Feedback Forum
2008-11-16 20:00:35 [Annemiek Hoofman] [reply] 
Je hebt de verkeerde module toegepast. Testing sample mean whit known variance. Ook al bedraagt de nulhypothese 15.2% i.p.v. 15%, dan nog ligt het steekproefgemiddelde (15.46%) lager dan de kritieke waarde en ligt het dus in het betrouwbaarheidsinterval.
2008-11-17 09:18:18 [Ken Wright] [reply] 
verkeerde module, juiste link:http://www.freestatistics.org/blog/index.php?v=date/2008/Nov/12/t1226487227v5w4apb00sdzsok.htm

hier moet je ook zien of 0.152 in het confidence interval ligt, en dit is effectief het geval 0.152<0.18..
2008-11-18 14:08:47 [Julie Govaerts] [reply] 
Ook al gaan we uit van een nulhypothese van 15.2% i.p.v. 15%, dan nog ligt het gemiddelde van de steekproef 0.1546 lager dan 0.189276559191704 en dus binnen het 95%-betrouwbaarheidsinterval.
2008-11-18 17:30:34 [72e979bcc364082694890d2eccc1a66f] [reply] 
Ook hier moet er gebruik gemaakt worden van Testing mean with known variance - Sample size en de rechterkant van de 1-sided test.
Hieruit kan je dan afleiden dat 15,46% nog steeds binnen het betrouwbaarheidsinterval ligt.
2008-11-23 15:49:04 [Hannes Van Hoof] [reply] 
De foute module is gebruikt, de juiste is: Testing Sample Mean with known Variance – Conidence Interval. als we er van uitgaan dat het vetpercentage 15.2 is ipv 15, dan nog ligt de 15.46% binnen het 95% betrouwbaarheids inetrval. (want 15.46 is lager dan 18.66)
2008-11-23 22:58:58 [Anouk Greeve] [reply] 
Zoals de anderen reeds zeiden; Testing sample mean with known variance is de juiste module. We gebruiken one-sided confidence interval van de right-tail. De rechterstaart is nauwkeuriger omdat de volledige 5% (foutmarge) toegewezen wordt aan de rechterkant.Ook al gaan we uit van een nulhypothese van 15,2% ipv 15%, dan nog ligt het gemiddelde van de steekproef 0,1546 lager dan de 0,18928 en dus binnen het 95%-betrouwbaarheidsinterval.

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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 time0 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 & 0 seconds \tabularnewline
R Server & 'Gwilym Jenkins' @ 72.249.127.135 \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=24491&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]0 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=24491&T=0

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=24491&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 time0 seconds
R Server'Gwilym Jenkins' @ 72.249.127.135






Testing Variance - Confidence Intervals for Sample Variance
Sample size27
Null hypothesis (H0)0.152
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.950.08093359835635220.245089302101761
Left one-sided confidence interval at 0.950.0899089154098378+inf
Right one-sided confidence interval at 0.9500.227328502934391
more information about confidence interval

\begin{tabular}{lllllllll}
\hline
Testing Variance - Confidence Intervals for Sample Variance \tabularnewline
Sample size & 27 \tabularnewline
Null hypothesis (H0) & 0.152 \tabularnewline
Confidence interval & 0.95 \tabularnewline
Type of Interval & Left tail & Right tail \tabularnewline
Two-sided confidence interval at  0.95 & 0.0809335983563522 & 0.245089302101761 \tabularnewline
Left one-sided confidence interval at  0.95 & 0.0899089154098378 & +inf \tabularnewline
Right one-sided confidence interval at  0.95 & 0 & 0.227328502934391 \tabularnewline
more information about confidence interval \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=24491&T=1

[TABLE]
[ROW][C]Testing Variance - Confidence Intervals for Sample Variance[/C][/ROW]
[ROW][C]Sample size[/C][C]27[/C][/ROW]
[ROW][C]Null hypothesis (H0)[/C][C]0.152[/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]0.0809335983563522[/C][C]0.245089302101761[/C][/ROW]
[ROW][C]Left one-sided confidence interval at  0.95[/C][C]0.0899089154098378[/C][C]+inf[/C][/ROW]
[ROW][C]Right one-sided confidence interval at  0.95[/C][C]0[/C][C]0.227328502934391[/C][/ROW]
[ROW][C]more information about confidence interval[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=24491&T=1

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=24491&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 Sample Variance
Sample size27
Null hypothesis (H0)0.152
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.950.08093359835635220.245089302101761
Left one-sided confidence interval at 0.950.0899089154098378+inf
Right one-sided confidence interval at 0.9500.227328502934391
more information about confidence interval


Figures (Output of Computation)

Input Parameters & R Code

Parameters (Session):
par1 = 27 ; par2 = 0.152 ; par3 = 0.95 ;
Parameters (R input):
par1 = 27 ; par2 = 0.152 ; 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
ua <- qchisq(halfalpha,df) * par2 / df
ub <- qchisq(1-halfalpha,df) * par2 / df
ua
ub
ul <- qchisq(1-par3,df) * par2 / df
ul
ur <- qchisq(par3,df) * par2 / df
ur
load(file='createtable')
a<-table.start()
a<-table.row.start(a)
a<-table.element(a,hyperlink('ht_variance.htm','Testing Variance - Confidence Intervals for Sample 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,'Null hypothesis (H0)',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#ex3', 'more information about confidence interval','example'),3,TRUE)
a<-table.row.end(a)
a<-table.end(a)
table.save(a,file='mytable.tab')