A small pilot study is run to determine the association between maternal age and birth weight. So fr

Question:

A small pilot study is run to determine the association between maternal age and birth weight. So from all the singleton births in 2009 at Hospital X with Moms aged ? 20 years, we randomly selected 17 records. We also selected randomly 17 records from all the singleton birth records with Moms aged > 20 years. Then we classified each infant as ? 2500 grams or > 2500 grams.

The data is given in the table below:

	Birthweight of Infants
Mom’s age	? 2500 grams	> 2500 grams	Total
? 20 years	5	12	17
> 20 years	4	13	17
Total	9	25	34

a) State the null and alternative hypotheses.

b) Using an alpha level of 0.05, perform the appropriate statistical test.

c) Explain carefully your results in 2-3 sentences.

d) If we extended the study and randomly selected 260 records from all the singleton births in 2009 at Hospital X (the data is shown below), would the maternal age be related to the birth-weight of the infant?