Need help working out sd/es

[essexboy]

Hi all, i was load testing my 6mm dasher the other day using viht n550 and came across a load which showed promise, i logged the speed but old 6 thumbs here pressed the wrong button and lost the sd/es readings, if one of you fine chaps could work them out for me i would be in your debt.

Vel readings where 2911 2913 2911 2916 2917

Regards

Steve

 

[fivering]

Try www.hubpages.com/hub/deviation

 

[RonAKA]

Vel readings where 2911 2913 2911 2916 2917

Steve, Standard Deviation works out to 2.8, and Extreme Spread is just 2917 minus 2911, or 6.

Unfortunately sample sizes this small are rather meaningless. I start to pay attention to SD at around 10 samples, and ideally you want 20 to 25. There is a lot of luck of the draw in ES, and for predicting future velocities I have never seen the value in it.

 

[essexboy]

Thankyou very much i shall continue testing and use your advise.

Regards
Steve