source("http://192.38.117.59/~linearpredictors/datafiles/readFever.R")

## Table of fever against fetal deaths.
(t1 <- table(fever$episodes,dnn = c("Number of fever episodes")))

## total no of episodes is the sum of "cases * no of episodes for that case".
no.episodes <-  sum(t1 * as.numeric(dimnames(t1)[[1]]))
no.women <- nrow(fever[!is.na(fever$episodes),])

## estimated probability 
p.hat <- no.episodes/(no.women*14)

## expected numbers of episodes
exp1 <- round(dbinom(0:10, 14, 0.0143)*no.women, digits=1)

## now we collapse the groups with 3 or more fever episodes
O <- c(t1[1:3], sum(t1[4:9]))
names(O) <- c("0", "1", "2", "3+")
E <- c(exp[1:3], sum(exp[4:9]))
names(E) <- c("0", "1", "2", "3+")

O-E

round((O-E)^2/E, digits = 2)