1. Assume that 300 students who're fans of TV show "The Office" are sampled and 231 of them had GPAs higher than 2.5. Then 400 students who dislike that TV show are sampled and 272 of them have GPAs higher than 2.5. Find out the 95% confidence interval for difference between proportions of students having GPAs higher than 2.5.
1.(-1.96,1.96)
2.(0.68,0.77)
3.(0.023,0.157)
4.(0.056,0.124)
5. None of above (do allow for slight rounding errors or table differences in selecting your solution)
2. All else being equal, what takes place to your confidence interval when you raise the value of alpha?
1. Your probability (confidence) raises and your interval gets wider
2. Your probability (confidence) reduces and your interval gets wider
3. Your probability (confidence) raises and your interval gets narrower
4. Your probability (confidence) reduces and your interval gets narrower
5. None of the above