[R] Poission distribution

[Peter Dalgaard]

"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             Øster 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