Abstract
Let X 1,X 2 be independent geometric random variables with parameters p 1,p 2, respectively, and Y 1,Y 2 be i.i.d. geometric random variables with common parameter p. It is shown that X 2:2, the maximum order statistic from X 1,X 2, is larger than Y 2:2, the second order statistic from Y 1,Y 2, in terms of the hazard rate order [usual stochastic order] if and only if \(p\geq \tilde{p}\), where \(\tilde{p}=(p_{1}p_{2})^{\frac{1}{2}}\) is the geometric mean of (p 1,p 2). This result answers an open problem proposed recently by Mao and Hu (Probab. Eng. Inf. Sci. 24:245–262, 2010) for the case when n=2.
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References
Balakrishnan, N., & Rao, C. R. (1998a). Handbook of statistics. Vol. 16: Order statistics: theory and methods. Amsterdam: Elsevier.
Balakrishnan, N. & Rao, C. R. (1998b). Handbook of statistics. Vol. 17: Order statistics: applications. Amsterdam: Elsevier.
Bon, J. L., & Pǎltǎnea, E. (2006). Comparisons of order statistics in a random sequence to the same statistics with i.i.d. variables. ESAIM: Probability and Statistics, 10, 1–10.
Dykstra, R., Kochar, S. C., & Rojo, J. (1997). Stochastic comparisons of parallel systems of heterogeneous exponential components. Journal of Statistical Planning and Inference, 65, 203–211.
Jeske, D. R., & Blessinger, T. (2004). Tunable approximations for the mean and variance of heterogeneous geometrically distributed random variables. The American Statistician, 58, 322–327.
Khaledi, B. E., & Kochar, S. C. (2000). Some new results on stochastic comparisons of parallel systems. Journal of Applied Probability, 37, 283–291.
Khaledi, B. E., & Kochar, S. C. (2002). Stochastic orderings among order statistics and sample spacings. In J. C. Misra (Ed.). Uncertainty and optimality-probability, statistics and operations research (pp. 167–203). Singapore: World Scientific.
Khaledi, B. E., & Kochar, S. C. (2007). Stochastic orderings of order statistics of independent random variables with different scale parameters Communications in Statistics. Theory and Methods, 36, 1441–1449
Kochar, S. C., & Xu, M. (2007a). Some recent results on stochastic comparisons and dependence among order statistics in the case of PHR model. Journal of Iranian Statistical Society, 6, 125–140.
Kochar, S. C., & Xu, M. (2007b). Stochastic comparisons of parallel systems when components have proportional hazard rates. Probability in the Engineering and Informational Science, 21, 597–609.
Kochar, S. C., & Xu, M. (2009). Comparisons of parallel systems according to the convex transform order. Journal of Applied Probability, 46, 342–352.
Lundberg, B. (1955). Fatigue life of airplane structures. Journal of the Aeronautical Sciences, 22, 394.
Mao, T., & Hu, T. (2010). Equivalent characterizations on orderings of order statistics and sample ranges. Probability in the Engineering and Informational Sciences, 24, 245–262.
Margolin, B. H., & Winokur, H. S. (1967). Exact moments of the order statistics of the geometric distribution and their relation to inverse sampling and reliability of redundant systems. Journal of the American Statistical Association, 62, 915–925.
Müller, A., & Stoyan, D. (2002). Comparison methods for stochastic models and risks. New York: Wiley.
Pǎltǎnea, E. (2008). On the comparison in hazard rate ordering of fail-safe systems. Journal of Statistical Planning and Inference, 138, 1993–1997.
Pledger, P., & Proschan, F. (1971). Comparisons of order statistics and of spacings from heterogeneous distributions. In J. S. Rustagi (Ed.), Optimizing methods in statistics (pp. 89–113). New York: Academic Press.
Proschan, F., & Sethuraman, J. (1976). Stochastic comparisons of order statistics from heterogeneous populations, with applications in reliability. Journal of Multivariate Analysis, 6, 608–616.
Shaked, M., & Shanthikumar, J. G. (2007). Stochastic orders. New York: Springer.
Weiss, G. (1962). On certain redundant systems which operate at discrete times. Technometric, 4, 68–74.
Xu, M., & Hu, T. (2011). Order statistics from heterogeneous negative binomial random variables. Probability in the Engineering and Information Sciences, 25, 435–448.
Zhao, P., & Balakrishnan, N. (2009). Characterization of MRL order of fail-safe systems with heterogeneous exponentially distributed components. Journal of Statistical and Planning Inference, 139, 3027–3037.
Zhao, P., & Balakrishnan, N. (2011a). Some characterization results for parallel systems with two heterogeneous exponential components. Statistics, 45, 593–604.
Zhao, P., & Balakrishnan, N. (2011b). MRL ordering of parallel systems with two heterogeneous components. Journal of Statistical and Planning Inference, 141, 631–638.
Zhao, P., Li, X., & Balakrishnan, N. (2009). Likelihood ratio order of the second order statistic from independent heterogeneous exponential random variables. Journal of Multivariate Analysis, 100, 952–962.
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We would like to thank the editor and anonymous referees for careful reading of the manuscript and valuable comments and suggestions, which resulted in an improvement in the presentation of this manuscript.
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This work was supported by National Natural Science Foundation of China (11001112).
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Zhao, P., Su, F. On maximum order statistics from heterogeneous geometric variables. Ann Oper Res 212, 215–223 (2014). https://doi.org/10.1007/s10479-012-1158-6
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DOI: https://doi.org/10.1007/s10479-012-1158-6