In a Study of the Relationship Between Birth Order and University

Essay

In a study of the relationship between birth order and university success, an investigator found that 140 in a sample of 200 university graduates were firstborn or only children. In a sample of 120 nongraduates 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.