Question

4. The effectiveness of two methods of teaching statistics is compared. A class of 24 stu dents is randomly divided into 2 groups and each group is taught according to a different method. The test scores of the two groups at the end of the semester show the following Group 1: n 874.52-112.6 Group 2: n2 -11 j 71.8 s 82.6 (a) Assuming underlying independent normal distributions with σ| σ , find a 98% (b) Does there appear to be a difference in teaching methods, based on the confidence characteristics: confidence interval for 2. interval you found in Question 4a? Why or why not? 5. Use the setup from Question 4 to answer the following questions (a) Compute a 90% confidence interval for σ/ , the ratio of the population variances. (b) Do we have a reason to believe that ởi and σ| are equal, based on the confidence interval you found in Question 5a? Why or why not?

Answer 1