Posted by **heather** on Wednesday, October 21, 2009 at 5:09pm.

A test of writing ability is given to a random sample of students before and after they completed a formal writing course. The results are given below. Construct a 99% confidence interval for the mean difference between the before and after scores. You may assume the populations are normally distributed.

Before 70 80 92 99 93 97 76 63 68 71 74

After 69 79 90 96 91 95 75 64 62 64 76

## Answer This Question

## Related Questions

- statistics - A test of writing ability is given to a random sample of students ...
- Statistics - These are the only ones that I am having problems with. Please help...
- Statistics - You are given the following information obtained from a random ...
- statistics - Randomly selected students participated in an experiment to test ...
- statistics - A simple random sample of students is selected, and the students ...
- Statistics - Thirty random students took a calc test. If the sample mean was 90...
- statistics - a random sample of 80 college students was selected to participate ...
- statistics - In a study designed to test the effectiveness of magnets for ...
- Statistics - Help me understand this problem, I have several more like this & ...
- statistics - A researcher hypothesizes that individuals who listen to classical...

More Related Questions