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Description of Statistical Computation

Author's title

Author*The author of this computation has been verified*
R Software Modulerwasp_hypothesismean5.wasp
Title produced by softwareTesting Population Mean with known Variance - Confidence Interval
Date of computationTue, 11 Nov 2008 03:33:03 -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/11/t1226399627wo35gydc3nrwaea.htm/, Retrieved Sun, 19 May 2024 10:07:14 +0000
Statistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?pk=23286, Retrieved Sun, 19 May 2024 10:07:14 +0000
QR Codes:

Original text written by user:
IsPrivate?No (this computation is public)
User-defined keywords
Estimated Impact150

Tree of Dependent Computations

Family? (F = Feedback message, R = changed R code, M = changed R Module, P = changed Parameters, D = changed Data)
F       [Testing Population Mean with known Variance - Confidence Interval] [Pork quality test Q5] [2008-11-11 10:33:03] [821c4b3d195be8e737cf8c9dc649d3cf] [Current]
F   P     [Testing Population Mean with known Variance - Confidence Interval] [Q5] [2008-11-12 14:29:33] [a0c3f7f6bb6d3d65b8bcf25e6a3c7584]
F         [Testing Population Mean with known Variance - Confidence Interval] [] [2008-11-12 14:30:30] [8d2ae74f923b31b35e9e42977c3c4399]
Feedback Forum
2008-11-20 13:22:49 [Gert-Jan Geudens] [reply] 
Het antwoord van de student is niet helemaal correct. Er ontbreekt de argumentatie voor de one-tailed test. We gebruiken deze omdat we een vermoeden van teveel vet hebben.
De student maakt tevens een interval door de Left one-sided confidence interval at 0.95 en right one-sided confidence interval at 0.95 te gebruiken. Uiteraard is dit verkeerd. We gebruiken enkel de right one-sided confidence interval wegens het vermoeden van teveel vet. Het betrouwbaarheidsinterval is dan gelijk aan '-oneindig ; 18.92%' Het steekproefgemiddelde ligt mooi binnen deze interval en dus is er geen enkel probleem.
2008-11-23 15:07:58 [Maarten Van Gucht] [reply] 
We moeten het one-sided confidence interval met de right tail gebruiken, omdat enkel de afwijkingen van het vetpercentage naar boven toe een economisch voordeel bieden. De student heeft hier rekening gehouden met alle intervallen, wat niet juist is.
De rechter staart is nauwkeuriger, omdat de volledige 5% toegewezen wordt aan de rechterkant.
De sample mean ( 15,46%) ligt onder de grens van het betrouwbaarheidsinterval (18,92%). We kunnen dus zeggen dat deze waarde binnen het betrouwbaarheidsinterval ligt.
2008-11-23 18:53:56 [Aurélie Van Impe] [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. Wat de student deed is dus fout, hij gebruikte de beide kanten voor het betrouwbaarheidsinterval. De sample mean ( 15,46%) ligt onder de grens van het betrouwbaarheidsinterval (18,92%). We kunnen dus zeggen dat deze waarde binnen het betrouwbaarheidsinterval ligt.
2008-11-24 10:27:01 [Lennart Holemans] [reply] 
Om deze opdracht te maken, moet je het one-sided interval met de right tail gebruiken, omdat we ons enkel interesseren in de afwijkingen van het vetpercentage naar boven toe doordat dat een economisch voordeel biedt. De student is dus fout door met alle intervallen rekening te houden, wat niet nodig is.
De sample mean ligt binnen het 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 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=23286&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=23286&T=0

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=23286&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 Population Mean with known Variance
Population variance0.012
Sample size27
Sample mean0.1546
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.950.1132803311796960.195919668820304
Left one-sided confidence interval at 0.950.119923440808296+inf
Right one-sided confidence interval at 0.95-inf0.189276559191704
more information about confidence interval

\begin{tabular}{lllllllll}
\hline
Testing Population Mean with known Variance \tabularnewline
Population variance & 0.012 \tabularnewline
Sample size & 27 \tabularnewline
Sample mean & 0.1546 \tabularnewline
Confidence interval & 0.95 \tabularnewline
Type of Interval & Left tail & Right tail \tabularnewline
Two-sided confidence interval at  0.95 & 0.113280331179696 & 0.195919668820304 \tabularnewline
Left one-sided confidence interval at  0.95 & 0.119923440808296 & +inf \tabularnewline
Right one-sided confidence interval at  0.95 & -inf & 0.189276559191704 \tabularnewline
more information about confidence interval \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=23286&T=1

[TABLE]
[ROW][C]Testing Population Mean with known Variance[/C][/ROW]
[ROW][C]Population variance[/C][C]0.012[/C][/ROW]
[ROW][C]Sample size[/C][C]27[/C][/ROW]
[ROW][C]Sample mean[/C][C]0.1546[/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]0.113280331179696[/C][C]0.195919668820304[/C][/ROW]
[ROW][C]Left one-sided confidence interval at  0.95[/C][C]0.119923440808296[/C][C]+inf[/C][/ROW]
[ROW][C]Right one-sided confidence interval at  0.95[/C][C]-inf[/C][C]0.189276559191704[/C][/ROW]
[ROW][C]more information about confidence interval[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=23286&T=1

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=23286&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 Population Mean with known Variance
Population variance0.012
Sample size27
Sample mean0.1546
Confidence interval0.95
Type of IntervalLeft tailRight tail
Two-sided confidence interval at 0.950.1132803311796960.195919668820304
Left one-sided confidence interval at 0.950.119923440808296+inf
Right one-sided confidence interval at 0.95-inf0.189276559191704
more information about confidence interval


Figures (Output of Computation)

Input Parameters & R Code

Parameters (Session):
par1 = 0.012 ; par2 = 27 ; par3 = 0.1546 ; par4 = 0.95 ;
Parameters (R input):
par1 = 0.012 ; par2 = 27 ; par3 = 0.1546 ; par4 = 0.95 ;
R code (references can be found in the software module):
par1<-as.numeric(par1)
par2<-as.numeric(par2)
par3<-as.numeric(par3)
par4<-as.numeric(par4)
sigma <- sqrt(par1)
sqrtn <- sqrt(par2)
ua <- par3 - abs(qnorm((1-par4)/2))* sigma / sqrtn
ub <- par3 + abs(qnorm((1-par4)/2))* sigma / sqrtn
ua
ub
ul <- par3 - qnorm(par4) * sigma / sqrtn
ul
ur <- par3 + qnorm(par4) * sigma / sqrtn
ur
load(file='createtable')
a<-table.start()
a<-table.row.start(a)
a<-table.element(a,hyperlink('ht_mean_knownvar.htm','Testing Population Mean with known Variance','learn more about Statistical Hypothesis Testing about the Mean when the Variance is known'),3,TRUE)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Population variance',header=TRUE)
a<-table.element(a,par1,2)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Sample size',header=TRUE)
a<-table.element(a,par2,2)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Sample mean',header=TRUE)
a<-table.element(a,par3,2)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Confidence interval',header=TRUE)
a<-table.element(a,par4,2)
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 ',par4), 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 ',par4), 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 ',par4), header=TRUE)
a<-table.element(a,'-inf')
a<-table.element(a,ur)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a, hyperlink('ht_mean_knownvar.htm#ex5', 'more information about confidence interval','example'),3,TRUE)
a<-table.row.end(a)
a<-table.end(a)
table.save(a,file='mytable.tab')