EnvStats (version 2.8.1)

Grice.Bain.80.mat: Adjusted Alpha Levels to Compute Confidence Intervals for the Mean of a Gamma Distribution

Description

Adjusted alpha levels to compute confidence intervals for the mean of a gamma distribution, as presented in Table 2 of Grice and Bain (1980).

Usage

data("Grice.Bain.80.mat")

Format

A matrix of dimensions 5 by 7, with the first dimension indicating the sample size (between 5 and Inf), and the second dimension indicating the assumed significance level associated with the confidence interval (between 0.005 and 0.25). The assumed confidence level is 1 - assumed significance level.

Details

See Grice and Bain (1980) and the help file for egamma for more information. The data in this matrix are used when the function egamma is called with ci.method="chisq.adj".

References

Grice, J.V., and L.J. Bain. (1980). Inferences Concerning the Mean of the Gamma Distribution. Journal of the American Statistical Association 75, 929-933.

USEPA. (2002). Estimation of the Exposure Point Concentration Term Using a Gamma Distribution. EPA/600/R-02/084. October 2002. Technology Support Center for Monitoring and Site Characterization, Office of Research and Development, Office of Solid Waste and Emergency Response, U.S. Environmental Protection Agency, Washington, D.C.

USEPA. (2015). ProUCL Version 5.1.002 Technical Guide. EPA/600/R-07/041, October 2015. Office of Research and Development. U.S. Environmental Protection Agency, Washington, D.C.

Examples

  # Look at Grice.Bain.80.mat

  Grice.Bain.80.mat
  #         alpha.eq.005 alpha.eq.01 alpha.eq.025 alpha.eq.05 alpha.eq.075
  #n.eq.5         0.0000      0.0000       0.0010      0.0086       0.0234
  #n.eq.10        0.0003      0.0015       0.0086      0.0267       0.0486
  #n.eq.20        0.0017      0.0046       0.0159      0.0380       0.0619
  #n.eq.40        0.0030      0.0070       0.0203      0.0440       0.0685
  #n.eq.Inf       0.0050      0.0100       0.0250      0.0500       0.0750

  #         alpha.eq.10 alpha.eq.25
  #n.eq.5        0.0432      0.2038
  #n.eq.10       0.0724      0.2294
  #n.eq.20       0.0866      0.2403
  #n.eq.40       0.0934      0.2453
  #n.eq.Inf      0.1000      0.2500