Help with Confidence Intervals

[HotBlack]

Hi,

Im new here and have no real background in statictics so please be patient but I really need some help on the subject of confidence intervals.

I have conducted a listening test with three various coding formats (MP3, AAC and WAV), 9 people have taken the test and given each codec a score of 0-100 (with 100 meaning the audio is indistinguishable from the reference audio).

In order to make a graph for the results I took an average of all the results for MP3, AAC etc and used those vaules to plot the graph.

All seemed find until my employer mentioned confidence intervals. He wants me to find the "95% Confidence Intervals" so we could back up the results professionally. I'm ashamed to say I have no background in statistics since I could never fins a teacher that could explain it well, coupled with my dyscalculia I just never looked near the subject.

I have tried google for info on this subject but i'm more confused than ever, any help would be appreciated.

Thanks,

[babucher]

Pick up:

1. Statistics for Experimenters by Box, Hunter and Hunter, 1st edition used on amazon for $10.
2. Statistics by McClave and Sincich, 9th edition used on amazon for $2.