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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 computationMon, 25 Oct 2010 20:17:47 +0000
Cite this page as followsStatistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?v=date/2010/Oct/25/t1288037859lmmunp9mj7xgxq5.htm/, Retrieved Mon, 29 Apr 2024 19:53:41 +0000
Statistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?pk=88483, Retrieved Mon, 29 Apr 2024 19:53:41 +0000
QR Codes:

Original text written by user:
IsPrivate?No (this computation is public)
User-defined keywords
Estimated Impact178

Tree of Dependent Computations

Family? (F = Feedback message, R = changed R code, M = changed R Module, P = changed Parameters, D = changed Data)
-     [Factor Analysis] [Sleep in Mammals ...] [2010-03-21 11:39:53] [b98453cac15ba1066b407e146608df68]
- RMPD  [Testing Mean with unknown Variance - Critical Value] [Hypothesis Test a...] [2010-10-19 11:45:26] [b98453cac15ba1066b407e146608df68]
F   PD    [Testing Mean with unknown Variance - Critical Value] [WS4 Taak 5 ] [2010-10-25 19:09:59] [c289bfbb56808c5d93a0f55b5d39f5bd]
F RM D        [Testing Variance - Critical Value (Region)] [WS 4 Taak 8 ] [2010-10-25 20:17:47] [3ee4962e6ce79244b15c133e74cea133] [Current]
Feedback Forum
2010-10-31 12:34:26 [48eb36e2c01435ad7e4ea7854a9d98fe] [reply] 
Hierover een toets doen wat betreft de mannelijke populatie is totaal overbodig. Dit omdat wanneer we - in bijvoorbeeld excel - de variantie berekenen voor de mannen we zien dat deze exact gelijk is aan 13. Uitspraken en berekeningen doen over het al dan niet significant verschillend zijn van deze variantie is dan ook totaal overbodig.

Wat betreft de vrouwelijke populatie zit er een foutje in de ingevoerde gegevens. De nulhypothese is hier namelijk 13 en niet meer de 20 uit de vorige vragen. Een correcte oefening zien we hier: http://www.freestatistics.org/blog/index.php?v=date/2010/Oct/25/t1288043532phj41g2mwbpfvum.htm/

Op basis van deze gegevens zien we dat we de nulhypothese mogen verwerpen. We zien dat de kritieke waarde (13,775) groter is dan de nulhypothese (13). Hieruit concluderen we dat de variantie bij de vrouwelijke populatie significant groter is dan 13.
2010-11-02 20:31:57 [23c3e34d843bca32d327eaf7dc6bdb2b] [reply] 
De berekening voor mannelijke studenten is hier inderdaad overbodig. De standaarddeviatie en de sample size is al berekend in excel. De nulhypothese is hier gelijke aan de sample variantie, die gelijk is aan 13 dus moeten we de hypothese niet berekenen voor mannelijke studenten.

De nulhypothese bij de vrouwelijke studenten moet dan 13 zijn in plaats van 20. Dan zien we dat de berekening voor vrouwelijke studenten ons aantoont dat de kritieke waarde gelijk is aan 13,775. We kunnen besluiten dat de vrouwelijke I1 variantie groter is dan 13 (aan de 35% type I error).

Uiteindelijk kunnen we besluiten dat de vrouwelijke I1 variantie niet significant verschillend is van 13 maar wel significant groter is dan 13.


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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=88483&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=88483&T=0

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=88483&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 - Critical value (region)
Sample size63
Sample variance13
Null hypothesis (H0)20
Type I error (alpha)0.35
Critical value18.4416628480944
ConclusionReject the null hypothesis

\begin{tabular}{lllllllll}
\hline
Testing Variance - Critical value (region) \tabularnewline
Sample size & 63 \tabularnewline
Sample variance & 13 \tabularnewline
Null hypothesis (H0) & 20 \tabularnewline
Type I error (alpha) & 0.35 \tabularnewline
Critical value & 18.4416628480944 \tabularnewline
Conclusion & Reject the null hypothesis \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=88483&T=1

[TABLE]
[ROW][C]Testing Variance - Critical value (region)[/C][/ROW]
[ROW][C]Sample size[/C][C]63[/C][/ROW]
[ROW][C]Sample variance[/C][C]13[/C][/ROW]
[ROW][C]Null hypothesis (H0)[/C][C]20[/C][/ROW]
[ROW][C]Type I error (alpha)[/C][C]0.35[/C][/ROW]
[ROW][C]Critical value[/C][C]18.4416628480944[/C][/ROW]
[ROW][C]Conclusion[/C][C]Reject the null hypothesis[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=88483&T=1

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=88483&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 size63
Sample variance13
Null hypothesis (H0)20
Type I error (alpha)0.35
Critical value18.4416628480944
ConclusionReject the null hypothesis


Figures (Output of Computation)

Input Parameters & R Code

Parameters (Session):
par1 = 0.95 ; par2 = 20 ;
Parameters (R input):
par1 = 63 ; par2 = 13 ; par3 = 20 ; par4 = 0.35 ;
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')