Wolfgang, Even if we use a binomial prob. value of 0.5 (under null hypothesis), we will get 3.5% error at 95% CI. Maybe, they are rounding up to 4%! Siddeek Wolfgang Rolke wrote: > Today the following polling results were given on cnn.com for the > Presidential race: > > CNN/USA TODAY/GALLUP POLL > October 20-22 > Likely Voters' Choice for President > Bush 46% > Gore 44% > Nader 4% > Buchanan 1% > Sampling error: +/-4% pts > Sample size: 769 > > For details go to > http://www.cnn.com/2000/ALLPOLITICS/stories/10/23/tracking.poll/index.html > > I am wondering how they find the Sampling error of +/-4% pts. The usual > estimate for the standard error of a binomial would be (for Bush) > > SQRT(0.46*(1-0.46)/769) = 0.01797 > > The error in a 95% CI would then be 1.96*0.01797 = 3.5% > > and in a 99% CI it would be 2.576*0.01797 = 4.6% > > Am I doing something wrong here? > > Thanks > > Wolfgang
begin:vcard n:Siddeek;Shareef M. tel;fax:(907) 465-2604 Phone: (907) 465-6107 tel;work:P.O. Box 25526, Juneau, Alaska 99802-5526, U.S.A. x-mozilla-html:FALSE org:Alaska Department of Fish and Game;Division of Commercial Fisheries adr:;;;;;; version:2.1 email;internet:[EMAIL PROTECTED] title:Shellfish Biometrician fn:Shareef M. Siddeek end:vcard
