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Author's title

Author*The author of this computation has been verified*
R Software Modulerwasp_hypothesisvariance3.wasp
Title produced by softwareTesting Variance - Confidence Intervals for Sample Variance
Date of computationFri, 07 Nov 2008 06:14:12 -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/07/t122606368501b50hw1c3qc75s.htm/, Retrieved Sun, 19 May 2024 07:07:00 +0000
Statistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?pk=22489, Retrieved Sun, 19 May 2024 07:07:00 +0000
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Original text written by user:
IsPrivate?No (this computation is public)
User-defined keywords
Estimated Impact191

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] [ci2] [2008-11-07 13:14:12] [7596afe9a05f2a2719ece78b1b0e12e6] [Current]
Feedback Forum
2008-11-17 11:27:05 [Nicolaj Wuyts] [reply] 
Hier gebruik je: Testing population mean with known variance - Confidence interval. De populatie variantie is 0,012; De steekproefgrootte is 27, de steekproefmediaan is 0,1546 en het confidence interval is 0,95. We moeten hier kijken naar de one-tailed hypothese omdat we hier nog steeds spreken over een te veel aan vet in het vlees. Als we dan kijken naar het interval dat berekent wordt voor de one-tailed hypothese, zien we dat het interval loopt van 0.119923440808296 tot 0.189276559191704. Het steekproefgemiddelde behoort hier uiteraard toe.
2008-11-17 11:32:19 [Nicolaj Wuyts] [reply] 
Excuses voor mijn vorige post. Deze was eigenlijk het antwoord op vraag 5. Hier volgt het antwoord op vraag 6:
De bewerking is hier hetzelfde als bij de vorige vraag, enkel wordt de sample mean hier vervangen door 0,152. Ook bij dit vetpercentage bekom je dat het steekproefgemiddelde onder de rechter grens ligt van de one-tailed hypothese.
2008-11-24 16:36:44 [4679c4d03f1d346a85e79d87ba60ec2b] [reply] 
Ook hier de verkeerde methode en de verkeerde gegevens. Testing sample mean with known variance-confidence interval zou hier gebruikt moeten worden. Ook hier moet one-sided test toegepast worden. De rechterstaart is hier belangrijk, ze is hier nauwkeuriger omdat de foutmarge wordt toegewezen aan de rechterkant. De nulhypothese van 15.2% ligt binnen de 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 time2 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 & 2 seconds \tabularnewline
R Server & 'Gwilym Jenkins' @ 72.249.127.135 \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=22489&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]2 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=22489&T=0

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=22489&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 time2 seconds
R Server'Gwilym Jenkins' @ 72.249.127.135






Testing Variance - Confidence Intervals for Sample Variance
Sample size27
Null hypothesis (H0)15.2
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.958.0933598356352224.5089302101761
Left one-sided confidence interval at 0.958.99089154098378+inf
Right one-sided confidence interval at 0.95022.7328502934391
more information about confidence interval

\begin{tabular}{lllllllll}
\hline
Testing Variance - Confidence Intervals for Sample Variance \tabularnewline
Sample size & 27 \tabularnewline
Null hypothesis (H0) & 15.2 \tabularnewline
Confidence interval & 0.95 \tabularnewline
Type of Interval & Left tail & Right tail \tabularnewline
Two-sided confidence interval at  0.95 & 8.09335983563522 & 24.5089302101761 \tabularnewline
Left one-sided confidence interval at  0.95 & 8.99089154098378 & +inf \tabularnewline
Right one-sided confidence interval at  0.95 & 0 & 22.7328502934391 \tabularnewline
more information about confidence interval \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=22489&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]15.2[/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]8.09335983563522[/C][C]24.5089302101761[/C][/ROW]
[ROW][C]Left one-sided confidence interval at  0.95[/C][C]8.99089154098378[/C][C]+inf[/C][/ROW]
[ROW][C]Right one-sided confidence interval at  0.95[/C][C]0[/C][C]22.7328502934391[/C][/ROW]
[ROW][C]more information about confidence interval[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=22489&T=1

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=22489&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)15.2
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.958.0933598356352224.5089302101761
Left one-sided confidence interval at 0.958.99089154098378+inf
Right one-sided confidence interval at 0.95022.7328502934391
more information about confidence interval


Figures (Output of Computation)

Input Parameters & R Code

Parameters (Session):
par1 = 27 ; par2 = 15.2 ; par3 = 0.95 ;
Parameters (R input):
par1 = 27 ; par2 = 15.2 ; 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
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')