x <- 0:5
y <- c(92,68,28,11,1,0)
q <- ppois(x,mean(rep(x,y)))
n <- length(y)
p[1] <- q[1]
p[n] <- 1-q[n-1]
for (i in 2:(n-1))
    p<-q-q[i-1]
chisq.test(y,p=p)