2009-03-20, 11:16 PM
Hazzy Wrote:I know how to run a hypothesis test. My issue lies with obtaining a StdDev for the ratio of kills to deaths. ;[
I want to create a confidence interval for my KDR of a random game. I need a StdDev of the ratio before I can do that. Dividing means works fine. Dividing StdDev of both samples doesn't work out right...
My current data has:
Kills Deaths Mean 22 8 StdDev 6.3 4.12
This comes out to a Mean KDR of 2.67.
Sqrt(6.3^2/4.12^2)=1.53
Mean of 2.67, StdDev of 1.53... That strikes me as wrong, since almost a third of my games will have me with under 1.00 KDR. (Quick mental calculation that might be wrong)
Oh. Yeah, you couldn't just do that. The problem with dividing that way is that (kills - mean kills)/(deaths - mean deaths) doesn't equal (kills/deaths) - (mean kills/mean deaths).
I'm not entirely sure on what is valid though. Brb.