In a Study of the Relationship Between Birth Order and College

Essay

In a study of the relationship between birth order and college success, an investigator found that 140 in a sample of 200 college graduates were firstborn or only children. In a sample of 120 non-graduates of comparable age and socioeconomic background, the number of firstborn or only children was 66. Estimate the difference between the proportions of firstborn or only children in the two populations from which these samples were drawn. Use a 90% confidence interval and interpret your results.
The approximate 90% confidence interval is:
______________
Based on the interval above, is there a difference between the proportions of firstborn or only children in the two populations?
______________
Explain.
________________________________________________________