A study was recently published in Western Australia on the r

A study was recently published in Western Australia on the relationship between method of conception and prevalence of major birth defects.

The prevalence of at least one major birth defect among infants conceived naturally was 4.2%, based on a large sample of infants. Among 837 infants born as a result of IVF, 75 had at least one major birth defect.

1. How many infants with at least one birth defect would we expect among the 837 IVF infants if the true prevalence of at least one birth defect in the IVF group were the same as for infants conceived naturally?

2. Do an unusual number of infants have at least one birth defect in the IVF group? Why or why not?

3. In addition, data were also provided regarding specific birth defects. There were 6 chromosomal birth defects among the IVF infants. Also the prevalence of chromosomal birth defects among infants conceived naturally is 9/4000.

Are there an unusual number of chromosomal birth defects in the IVF group?

Solution