[R] Rv: Chi-square parameter estimation

From: Julio Rojas <jcredberry_at_ymail.com>
Date: Mon, 28 Jul 2008 05:38:05 -0700 (PDT)

Hi. I have made 100 experiments of an M/M/1 queue, and for each one I have calculated both, mean and variance of the queue size. Now, a professor has told me that variance is usually chi-squared distributed. Is there a way in R that I can find the parameter that best fits a chi-square to the variance data? I know there's fitdistr()m but this function doesn't handle chi-square. I believe the mean estimator for the chi-square is df (degrees of freedom). The theoretical variance for an M/M/1 queue with lambda=30/33 is ~108. So, should I expect the chi-square with parameter 108 is the one that best fits the data?

Thanks a lot for your help.

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