Inferences on the common mean of several normal populations under heteroscedasticity
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In this paper, we consider the problem of making inferences on the common mean of several normal populations when sample sizes and population variances are possibly unequal. We are mainly concerned with testing hypothesis and constructing confidence interval for the common normal mean. Several researchers have considered this problem and many methods have been proposed based on the asymptotic or approximation results, generalized inferences, and exact pivotal methods. In addition, Chang and Pal (Comput Stat Data Anal 53:321–333, 2008) proposed a parametric bootstrap (PB) approach for this problem based on the maximum likelihood estimators. We also propose a PB approach for making inferences on the common normal mean under heteroscedasticity. The advantages of our method are: (i) it is much simpler than the PB test proposed by Chang and Pal (Comput Stat Data Anal 53:321–333, 2008) since our test statistic is not based on the maximum likelihood estimators which do not have explicit forms, (ii) inverting the acceptance region of test yields a genuine confidence interval in contrast to some exact methods such as the Fisher’s method, (iii) it works well in terms of controlling the Type I error rate for small sample sizes and the large number of populations in contrast to Chang and Pal (Comput Stat Data Anal 53:321–333, 2008) method, (iv) finally, it has higher power than recommended methods such as the Fisher’s exact method.
KeywordsCommon normal mean Genuine confidence interval Monte Carlo simulation Parametric bootstrap
The authors would like to thank the referees for their constructive comments. The second author would like to acknowledge the Research Council of Shiraz University.
- Hartung J, Knapp G (2009) Exact and generalized confidence intervals in the common mean problem. In: Schipp B, Kräer W (eds) Statistical Inference, Econometric Analysis and Matrix Algebra, Physica-Verlag HD, pp 85–102Google Scholar
- Nasri A, Seyed Hosseini SJ (2014) The comparison of hepatic and biliary duct sonography accuracy performed by the emergency medicine and radiology residents in patients with right upper quadrant abdominal pain. Board Thesis, Tehran University of medical sciencesGoogle Scholar