Autism
		Autism	Typical development	Total
Periconceptional prenatal vitamin	No vitamin	111	70	181
Vitamin	143	159	302
	Total	254	229	483

Suppose that researchers set their hypotheses as "There is no association between prenatal vitamin use and autism".

a. What is the most appropriate statistical test? Also, set up corresponding hypotheses.

b. Calculate the expected frequencies of each cell. (Show all work for the full credit)

c. Calculate a corresponding test statistic. (Show all work for the full credit)

d. UsingStata, find a