In [1]:
x <- c(315,101,108,32)
n <- sum(x)

a)


In [2]:
p0 <- c(9,3,3,1)/16
chisq.test(x, p=p0)


Out[2]:
	Chi-squared test for given probabilities

data:  x
X-squared = 0.47002, df = 3, p-value = 0.9254

b)


In [3]:
L0 <- dmultinom(x, prob=p0)
Lhat <- dmultinom(x, prob=x/n)
(Lamb <- -2*log(L0/Lhat))
pchisq(Lamb, df=3, lower.tail=FALSE)


Out[3]:
0.475445238998873
Out[3]:
0.924251903974394

In [4]:
dchisq(0.95, df=1)


Out[4]:
0.254541374114313