# ::Free Statistics and Forecasting Software::

v1.2.1

### :: Testing Variance - Confidence Intervals for Sample Variance - Free Statistics Software (Calculator) ::

All rights reserved. The non-commercial (academic) use of this software is free of charge. The only thing that is asked in return is to cite this software when results are used in publications.

This free online software (calculator) computes the confidence intervals for the one-sided and two-sided hypothesis test about the sample variance (for a given sample size, null hypothesis, and confidence interval).

 Send output to: Browser Blue - Charts White Browser Black/White CSV Sample size Null Hypothesis about variance Confidence interval

 Source code of R 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 print(ua) print(ub) ul <- qchisq(1-par3,df) * par2 / df print(ul) ur <- qchisq(par3,df) * par2 / df print(ur) load(file="createtable") a<-table.start() a<-table.row.start(a) a<-table.element(a,"Testing Variance - Confidence Intervals for Sample 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.end(a) table.save(a,file="mytable.tab")
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 Cite this software as: Wessa P., (2016), Testing Sample Variance - Confidence Intervals (v1.0.3) in Free Statistics Software (v1.2.1), Office for Research Development and Education, URL http://www.wessa.net/rwasp_hypothesisvariance3.wasp/ The R code is based on : Xycoon, Statistics - Econometrics - Forecasting, Office for Research Development and Education, http://www.xycoon.com/ht_variance.htm#ex3
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