Birth certificates show that approximately 9% of all births in the United States are to teen mothers (ages 15 to 19), 24% to young‑adult mothers (age 20 to 24), and the remaining 67% to adult mothers (age 25 to 44). An extensive survey of live births examined pregnancy type, defining an unintended pregnancy as one that was unwanted or mistimed by at least two years. The survey found that "only 23% of births to teen mothers are intended, and 77% are unintended. Among births to young‑adult women age 20 – 24, 50% are intended, and at ages 25 – 44, 75% are intended."Use your tree diagram and Bayes’s theorem to find the probability that a birth was to a teen mother if we know that the pregnancy was unintended.

In a study of the relationship between socio-economic class and unethical behavior, 129 university of california undergraduates at berkeley were asked to identify themselves as having low or high social-class by comparing themselves to others with the most (least) money, most (least) education, and most (least) respected jobs. they were also presented with a jar of individually wrapped candies and informed that the candies were for children in a nearby laboratory, but that they could take some if they wanted. after completing some unrelated tasks, participants reported the number of candies they had taken. it was found that those who were identiď¬ed as upper-class took more candy than others. in this study, identify: (a) the cases, (b) the variables and their types, (c) the main research question, (d) identify the population of interest and the sample in this study, and (e) comment on whether or not the results of the study can be generalized to the population, and if the ď¬ndings of the study can be used to establish causal relationships.