The expected number of bladder cancer over next 20 years a tire industry is 1.8. Poission distribution is assumed to hold and 6 reported deaths are caused by bladder cancer among the employees. Trying to find how unusual this event is.> ppois(q=6, lambda=1.8, lower.tail = TRUE, log.p = FALSE)[1] 0.9974306 not sure if ppois is the right one to use and the parameters... thx much
"Ethan Johnsons" <ethan.johnsons at gmail.com> writes:> The expected number of bladder cancer over next 20 years a tire > industry is 1.8. Poission distribution is assumed to hold and 6 > reported deaths are caused by bladder cancer among the employees. > Trying to find how unusual this event is. > > > ppois(q=6, lambda=1.8, lower.tail = TRUE, log.p = FALSE) > [1] 0.9974306 > > not sure if ppois is the right one to use and the parameters...I think not. However, we're not doing your homework. Instead, do the following x <- 0:10 cbind(x, p=round(dpois(x, lambda=1.8),4)) plot(x, dpois(x, lambda=1.8), type="h", lwd=2) abline(v=6) then apply(brains)... -- O__ ---- Peter Dalgaard ?ster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907
Is that 6 deaths over 20 years? If so, the probability of getting exactly 6 deaths is given by> dpois(6,1.8)[1] 0.007808587 The probability of getting six or more deaths is 1 minus the result you obtained. On 20/09/06, Ethan Johnsons <ethan.johnsons at gmail.com> wrote:> The expected number of bladder cancer over next 20 years a tire > industry is 1.8. Poission distribution is assumed to hold and 6 > reported deaths are caused by bladder cancer among the employees. > Trying to find how unusual this event is. > > > ppois(q=6, lambda=1.8, lower.tail = TRUE, log.p = FALSE) > [1] 0.9974306 > > not sure if ppois is the right one to use and the parameters... > > thx much > > ______________________________________________ > R-help at 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. >-- ================================David Barron Said Business School University of Oxford Park End Street Oxford OX1 1HP -- ================================David Barron Said Business School University of Oxford Park End Street Oxford OX1 1HP