Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

تمرين 45

Critical Thinking: Different Confidence Levels
(a) Suppose that a 95% confidence interval for a difference of proportions contains both positive and negative numbers. Will a 99% confidence interval based on the same data necessarily contain both positive and negative numbers Explain. What about a 90% confidence interval Explain.
(b) Suppose that a 95% confidence interval for a difference of proportions contains all positive numbers. Will a 99% confident interval based on the same data necessarily contain all positive numbers as well Explain. What about a 90% confidence interval Explain.