In an effort to investigate how 10 college students retain information from a novel, a teacher shows them a movie about the novel after they read the book. A pre-test is given before the movie and a post-test is given after the movie. The results are below. a = 0.01. Can the teacher conclude the movie helped to improve the student's retention of information? Construct a 95% confidence interval for the mean difference in the number of points that changed between the pre-test and the post test after watching the movie. Interpret the confidence interval.

D = -4.5 S_{D}^{}= 4.79 n_{}= 10

#### Top Answer

The 't' test statistic = D / [S D /√n] = - 4.5/[4.79/√10] ... View the full answer

- a small typo error. Modified T critical value is = 2.2621, So the correct 95% CL = [ -7.9265, 1.0735 ]
- chinnaistats
- Jul 19, 2016 at 6:32pm

- should it be -7.9625, -10735
- PresidentHackerGrouse5435
- Jul 19, 2016 at 6:54pm

- should it be -7.9625, -1.0735
- PresidentHackerGrouse5435
- Jul 19, 2016 at 6:57pm

- upper limit is positive value
- chinnaistats
- Jul 19, 2016 at 6:59pm

- -7.9265, 1.0735
- chinnaistats
- Jul 19, 2016 at 6:59pm