statistic help again :(

[tris-]

im testing the repeatability for a weighing machine and using a students t number of 2.262. ive been reading around for about an hour now but none of the info seems appropriate and im not allowed to trust wikipedia.

what i would like to know in a nutshell is why such a number needs to be used. i grasped the idea that its used in conjunction with a standard deviation of a sample of a population. i just dont know WHY it needs to be put into the equation.

anyone?

 

[old.Tohtori]

I had a perfect "sexual innuendo" answer to this...but i was tired

 

[tris-]

I had a perfect "sexual innuendo" answer to this...but i was tired

i think it may of clouded your mind, there is nothing sexual about anything i typed

go shooter some whiskey old man

 

[old.Tohtori]

You obviously haven't read my reply to Bugzies thread way back...and how did you know i drink that stuff?

 

[Solo]

http://www.itl.nist.gov/div898/handbook/eda/section3/eda3672.htm

http://www.itl.nist.gov/div898/handbook/eda/section3/eda3672.htm

9 degrees of freedom with 0.025 chance of exceeding critical value ?

I think it is used to give a confidence interval of 5%, 0.05 which is a pretty standard interval for scientific data analysis.

 

[tris-]

http://www.itl.nist.gov/div898/handbook/eda/section3/eda3672.htm

http://www.itl.nist.gov/div898/handbook/eda/section3/eda3672.htm

9 degrees of freedom with 0.025 chance of exceeding critical value ?

I think it is used to give a confidence interval of 5%, 0.05 which is a pretty standard interval for scientific data analysis.

thats some handy info for sure. but what im more interested in is WHY it needs to be put into a calculation. i have 4 different things im multiplying together to give a repeatability reading. but why does 2.262 need to be there to give the correct answer?

ive done basic work with t numbers before but that was to find the t number and reject or accept an hypothesis. now this time im given a t number to put into a calculation. and omg, wtf kind of library is shut on a wednesday ffs

You obviously haven't read my reply to Bugzies thread way back...and how did you know i drink that stuff?

thats what all old bastards drink