Chelle

thanks for your response.isn’t it that the f distribution is for non-normal, and the t distribution for non normal? i saw it from various table in statistics book…

Thanks Dave.
I’m confused now of ANOVA… I read from a book that ANOVA is a test of means not a test of variance, howcome it uses the F table and not the t table? F distribution is for variance, so if ANOVA is a test of means it should therefore use the t table…
Pls help me clarify this…
Thanks again.

Hello Mr Sambuddha,Can you also send me the article on the 30 sample size that you sent to DT? I am also interested to know why 30? My email add is, [email protected]
Thanks,
Rechel

But what should I use in computing for cpk?

Hello Mike,How do you test medians?Thanks.

But isn’t it right that we do f-test first before we do t-test?

Hello Bob,Thanks for your response. If i will use I-MR, what should be the data coverage of the calculated control limits. Shall it cover the data from the time the tool is new up to the time the tool has deteriorated and needs to be changed when I compute for the control limits?Thanks,
Chelle

thanks darth! great help.

but how about the formula Rbar/d2?? what is this formula for?

hello matt,thanks! the link is really helpful, but how do we compute for stability/instability… as i can remember there is a statistical test that is used here… pls help.

hello matt,do you know a reference where I can read this?thanks,
rechel