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Description of Statistical Computation

Author's title

Author*The author of this computation has been verified*
R Software Modulerwasp_hypothesisvariance1.wasp
Title produced by softwareTesting Variance - Critical Value (Region)
Date of computationThu, 13 Nov 2008 01:45:44 -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/t1226566225mski8onl0g8s2nk.htm/, Retrieved Sun, 19 May 2024 11:30:47 +0000
Statistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?pk=24488, Retrieved Sun, 19 May 2024 11:30:47 +0000
QR Codes:

Original text written by user:
IsPrivate?No (this computation is public)
User-defined keywordshypothesis testing
Estimated Impact174

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 - Critical Value (Region)] [tinneke_debock.hy...] [2008-11-13 08:45:44] [20137734a2343a7bbbd59daaec7ad301] [Current]
Feedback Forum
2008-11-15 18:02:01 [Philip Van Herck] [reply] 
Het juiste antwoord is als volgt: De reductie in variantie is niet significant bij een type I error van 5%. Dit komt omdat de sample variance (4.2) groter is dan de critical value (4.19). Ook de berekende p-value (0.05229) is groter dan het percentage van de type I error (0.05). We kunnen ook besluiten dat de sample variance zich in de left-sided 95% confidence interval van (4.19;+oneindig) bevindt.
2008-11-24 17:51:03 [Marlies Polfliet] [reply] 
Het antwoord van de student is fout, er is geen sprake van een significant verschil. Dit kan men concluderen uit het feit dat de sample variance (4,2) groter is dan de critical value (4.19). Bovendien is ook de p-value (0,05229) groter dan de type I error (alfa) (= 0,05). De sample variance bevindt zich in de left-sided 95% confidence interval van 4.19 tot +oneindig.
2008-11-24 21:40:14 [Jonas Scheltjens] [reply] 
Men moet hier de oplossing verkrijgen dat het verschil in de variantie is niet significant verschillend, daar het verschil mogelijk wel te wijten is aan het toeval. De student heeft dit verkeerd. We kunnen de (niet-)significantie aan de hand van 3 elementen waarnemen: allereerst is de de kritische waarde (4,19) kleiner dan de sample variance (4,2). Ten tweede is de p-waarde gelijk aan 0,05229, wat groter is dan de Type 1 Error (0,05). Ten derde kunnen we de sample variance binnen de left-sided 95% conficence interval (4,19; +∞) terugvinden, en dit duidt op het feit dat het getoonde verschil enkel het toeval te wijten valt.

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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'Sir Ronald Aylmer Fisher' @ 193.190.124.24

\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 & 'Sir Ronald Aylmer Fisher' @ 193.190.124.24 \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=24488&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]'Sir Ronald Aylmer Fisher' @ 193.190.124.24[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=24488&T=0

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=24488&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'Sir Ronald Aylmer Fisher' @ 193.190.124.24






Testing Variance - Critical value (region)
Sample size320
Sample variance4.2
Null hypothesis (H0)4.8
Type I error (alpha)0.05
Critical value4.19241479848094
ConclusionThere is no reason to reject the null hypothesis

\begin{tabular}{lllllllll}
\hline
Testing Variance - Critical value (region) \tabularnewline
Sample size & 320 \tabularnewline
Sample variance & 4.2 \tabularnewline
Null hypothesis (H0) & 4.8 \tabularnewline
Type I error (alpha) & 0.05 \tabularnewline
Critical value & 4.19241479848094 \tabularnewline
Conclusion & There is no reason to reject the null hypothesis \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=24488&T=1

[TABLE]
[ROW][C]Testing Variance - Critical value (region)[/C][/ROW]
[ROW][C]Sample size[/C][C]320[/C][/ROW]
[ROW][C]Sample variance[/C][C]4.2[/C][/ROW]
[ROW][C]Null hypothesis (H0)[/C][C]4.8[/C][/ROW]
[ROW][C]Type I error (alpha)[/C][C]0.05[/C][/ROW]
[ROW][C]Critical value[/C][C]4.19241479848094[/C][/ROW]
[ROW][C]Conclusion[/C][C]There is no reason to reject the null hypothesis[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=24488&T=1

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=24488&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 - Critical value (region)
Sample size320
Sample variance4.2
Null hypothesis (H0)4.8
Type I error (alpha)0.05
Critical value4.19241479848094
ConclusionThere is no reason to reject the null hypothesis


Figures (Output of Computation)

Input Parameters & R Code

Parameters (Session):
par1 = 320 ; par2 = 4.2 ; par3 = 4.8 ; par4 = 0.05 ;
Parameters (R input):
par1 = 320 ; par2 = 4.2 ; par3 = 4.8 ; par4 = 0.05 ;
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)
df <- par1 - 1
if (par2 > par3)
{
myc <- par3 / df * qchisq(1-par4,df)
} else {
myc <- par3 / df * qchisq(par4,df)
}
myc
load(file='createtable')
a<-table.start()
a<-table.row.start(a)
a<-table.element(a,hyperlink('ht_variance.htm','Testing Variance - Critical value (region)','learn more about Statistical Hypothesis Testing about the Variance'),2,TRUE)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Sample size',header=TRUE)
a<-table.element(a,par1)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Sample variance',header=TRUE)
a<-table.element(a,par2)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Null hypothesis (H0)',header=TRUE)
a<-table.element(a,par3)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Type I error (alpha)',header=TRUE)
a<-table.element(a,par4)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Critical value',header=TRUE)
a<-table.element(a,myc)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'Conclusion',header=TRUE)
if (par2 > par3)
{
if (par2 < myc) a<-table.element(a,'There is no reason to reject the null hypothesis') else a<-table.element(a,'Reject the null hypothesis')
} else {
if (par2 > myc) a<-table.element(a,'There is no reason to reject the null hypothesis') else a<-table.element(a,'Reject the null hypothesis')
}
a<-table.row.end(a)
a<-table.end(a)
table.save(a,file='mytable.tab')