Question

Researchers studying the link between prenatal vitamin use and autism surveyed the mothers of a random sample of children aged 24 - 60 months with autism and conducted another separate random sample for children with typical development. The table below shows the number of mothers in each group who did and did not use prenatal vitamins during the three months before pregnancy (periconceptional period). Researchers studying the link between prenatal vit (a) State appropriate hypotheses to test for independence of use of prenatal vitamins during the three months before pregnancy and autism. (Think about the definition of independence and how that relates to proportions and the data given.) (b) Complete the hypothesis test and state an appropriate conclusion. (Reminder: verify any necessary conditions for the test.) (c) A New York Times article reporting on this study was titled

Answer 1

GIVEN DATA :

a)For independence of two variables,the chi-square test will be used.The hypothesis defined as :

H_{0 :} The use of prenatal vitamins during the 3 months before pregnancy is independent of not using the vitamins can cause autism.

H₁ : The use of prenatal vitamins during the 3 months before pregnancy is dependent of not using the vitamins can cause autism.

b) To obtain the result of the given hypothesis in the part a the below formula of test statistic is used.

Calculations in EXCEL :

The value of chi-square where degree of freedom is 1 and the value is 3.84 ,calculated value of chi-square is 8.865.

c)The title of the article is appropriate as there is a statistically difference that the dependency of having the vitamins to prevent the autism.