Within standard deviation formula

[#1]

Hi, can anyone help me ideally in excel to show me how Within sigma was calculated, I am able to get only Overall

 Thank you

[#2]

Hi @MichaH : Hopefully this answers your question.

https://community.jmp.com/t5/Discussions/Process-capability-within-sigma-estimation-for-different-nu....

[#3]

Hi,

I have subgroup size of 1, so not cleaver much...

[#4 · Accepted solution]

Actually, the picture you posted is using a moving range to estimate the within standard deviation.  The MR uses a surrogate subgroup size of 2 (previous-current).  You will need the average MR.

 estimated standard deviation = MR-bar/d2

[#5]

Hi,

stunning evening. Finally I got it and able to replicate by manual calculation. You saved my day. Thank you a lot.

Michal

[#6]

Why do you need to do this in Excel?

[#7]

Hi Jim,

because I need to understand the mechanism behind to explain others