Question

An article in the Journal of Family Psychology (March 2006) by research psychologist Scott Stanley, titled "Premarital Education, Marital Quality, and Marital Stability " presents evidence that pre-marital counseling helps to make marriages healthy and strong. Assuming the current divorce rate is 42%, this study suggests that for couples who participated in pre-marital counseling, the divorce rate is less. The study is based on n=3,000 couples and it found that 828 ended in divorce. Answer the following questions.

a. Calculate a two-sided 99% confidence interval for the true divorce rate (proportion) of couples who receive pre-marital counseling. Interpret your interval.

b. Perform a test to determine if the true proportion of couples divorcing who receive pre-marital counseling is less than the current divorce rate of 42%. Use alpha = 0.05 State the hypotheses (Ho, Ha), z*, p-value and conclusion.

c. Check the assumptions of the proportion test, do they pass?

1. Could you conclude that pre-martial counseling ‘statistically’ lowers the divorce rate? Please answer Yes or No and support your answer.
2. Someone suggested that pre-marital counseling reduces the risk of divorce by 50% (cuts the rate in half from 42% to 21%. Based on your interval in (1.), could that claim be reasonably made?
3. What are your views of pre-marital counseling? Does this study support or change your views on pre-marital counseling? Why or why not? (There is no wrong answer here)

Answer 1