Calculating standard deviation from histogram
Calculating standard deviation from histogram
(OP)
I have data in a histogram format that I want to calculate the standard deviation. See the attachment.
Any ideas short of reentering all 656 values in a column? Must be a better way.
Any ideas short of reentering all 656 values in a column? Must be a better way.
----------------------------------------
The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.





RE: Calculating standard deviation from histogram
Thickness 1, count = 2
Thickness 2, count = 3
Thickness 4, count = 5
Average = [(1*2) + (2*3) + (4*5)]/(2+3+5) = 2.8
STD = sqrt( [2*(1-2.8)^2 + 3*(2-2.8)^2 + 5*(4-2.8)^2]/(2+3+5))
I think.
RE: Calculating standard deviation from histogram
----------------------------------------
The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: Calculating standard deviation from histogram
http://files.engineering.com/download.aspx?folder=... which matches dgallup's answer
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Calculating standard deviation from histogram
----------------------------------------
The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.