Get the the package fortunes in the CRAN and try >fortune("Harrell") for experience of and advance R-user. For the second question, the binomial distribution converge to normal distribution asymptomaticaly. You can not expect get the same result by using the two approximations on a finite sample. Watching a football macth in a TV screen is not the same thing that see the game in a staduim. Justin BEM Elève Ingénieur Statisticien Economiste BP 294 Yaoundé. Tél (00237)9597295. ----- Message d'origine ---- De : Ethan Johnsons À : "Liaw, Andy" Cc : r-help@stat.math.ethz.ch Envoyé le : Jeudi, 19 Octobre 2006, 5h43mn 36s Objet : Re: [R] CI Thx so much. I just got into R world for my small research. I thought that R is free so doesn't have many features, but it seems I was wrong. Why do these two return different values? 0.2666456 0.6133544 0.2698531 0.6213784 I think the diff is ignorable, but would ask. ej On 10/19/06, Liaw, Andy wrote: > You did ask for CI of mean, so that's what you got. If you want CI for > proportion, here are two (non-bootstrap) ways: > > R> confint(lm(I(x == 1) ~ 1), level=.9) > 5 % 95 % > (Intercept) 0.2666456 0.6133544 > R> binom.test(sum(x == 1), length(x), conf.level=.9) > > Exact binomial test > > data: sum(x == 1) and length(x) > number of successes = 11, number of trials = 25, p-value = 0.69 > alternative hypothesis: true probability of success is not equal to 0.5 > 90 percent confidence interval: > 0.2698531 0.6213784 > sample estimates: > probability of success > 0.44 > > I hope these are not HW problems? > > Andy > > From: Ethan Johnsons > > > > Thank you so much for the feedback. > > > > The random numbers are working great. I have tried > > non-random numbers, and the outcome is not correct with confint. > > > > Is there a way to compute i.e. a 90% confidence interval for > > percent of 1? > > > > i.e. where 1 = apple; 2 = orange > > > > > x > > [1] 2 2 2 2 2 1 1 2 2 1 2 1 2 2 2 1 1 1 1 1 1 1 2 2 2 > > > table (x) > > x > > 1 2 > > 11 14 > > > > > x =11 > > > confint(lm(x~1), level=0.90) > > 5 % 95 % > > (Intercept) NaN NaN > > > > ej > > > > On 10/18/06, Liaw, Andy wrote: > > > Here's one way: > > > > > > R> x <- c(6,11,5,14,30,11,17,3,9,3,8,8) confint(lm(x~1), level=.9) > > > 5 % 95 % > > > (Intercept) 6.546834 14.2865 > > > > > > Andy > > > > > > From: Ethan Johnsons > > > > > > > > I have a quick question, please. > > > > > > > > Does R have function to compute i.e. a 90% confidence > > interval for > > > > the mean for these numbers? > > > > > > > > > mean (6,11,5,14,30,11,17,3,9,3,8,8) > > > > [1] 6 > > > > > > > > I thought pt or qt would give me the interval, but it seems not. > > > > > > > > thx much. > > > > > > > > ej > > > > > > > > ______________________________________________ > > > > R-help@stat.math.ethz.ch mailing list > > > > https://stat.ethz.ch/mailman/listinfo/r-help > > > > PLEASE do read the posting guide > > > > http://www.R-project.org/posting-guide.html > > > > and provide commented, minimal, self-contained, reproducible code. > > > > > > > > > > > > > > > > > > > > > > > ---------------------------------------------------------------------- > > > -------- > > > Notice: This e-mail message, together with any > > attachments, contains > > > information of Merck & Co., Inc. (One Merck Drive, > > Whitehouse Station, > > > New Jersey, USA 08889), and/or its affiliates (which may be known > > > outside the United States as Merck Frosst, Merck Sharp & > > Dohme or MSD > > > and in Japan, as Banyu - direct contact information for > > affiliates is > > > available at http://www.merck.com/contact/contacts.html) > > that may be > > > confidential, proprietary copyrighted and/or legally > > privileged. It is > > > intended solely for the use of the individual or entity > > named on this > > > message. If you are not the intended recipient, and have > > received this > > > message in error, please notify us immediately by reply e-mail and > > > then delete it from your system. > > > > > > > > ---------------------------------------------------------------------- > > > -------- > > > > > > > > > > > > ------------------------------------------------------------------------------ > Notice: This e-mail message, together with any attachment...{{dropped}} ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ___________________________________________________________________________ Découvrez une nouvelle façon d'obtenir des réponses à toutes vos questions ! [[alternative HTML version deleted]]