Dear Suzanne and interested others, The latest best practice I've run across is the Wilson method using Yates' continuity correction. It is formally described and advocated in the following articles:
Newcombe R.G. (1998) Two-Sided Confidence Intervals for the Single Proportion: Comparison of Seven Methods. Statistics in Medicine 17, 857872. Newcombe R.G. (1998) Interval Estimation for the Difference Between Independent Proportions: Comparison of Eleven Methods. Statistics in Medicine 17, 873890. If you use the stats language R, it's implemented using prop.test (which also allows two-sample testing of equal proportions). There's also a web interface at: http://faculty.vassar.edu/lowry/prop1.html Good luck, Phil At 10:37 PM 12/16/2007, Suzanne Griffin wrote: >Can anyone tell me how to compute CI's for a >proportion when the sample is fron from a finite >population? For example,?the population size is >100, I sample 50 individuals, and the event of >interest occurs in 20 cases. I want to put >confidence intervals around that 0.40. > >I would appreciate any guidance. > >Sue > >Suzanne Griffin >Wildlife Biology Program >College of Forestry and Conservation >University of Montana >Missoula, MT 59812 > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Phil Novack-Gottshall [EMAIL PROTECTED] Assistant Professor Department of Geosciences University of West Georgia Carrollton, GA 30118-3100 Phone: 678-839-4061 Fax: 678-839-4071 http://www.westga.edu/~pnovackg ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
