Calculating Conditional Standard Deviation?
It didn't work, unfortunately. :(
"T. Valko" wrote:
Try it like this: (array entered)
=STDEV(IF($E$2:$E$296=K17,$F$2:$F$296/1000000))
Biff
"Harimau" wrote in message
...
Hi there,
I have two columns - Industry Code and Market Cap. I want to create a
summary table for average market cap and standard deviation for certain
Industries. However, there are like 20 different industry codes and I
didn't
exactly feel like doing it manually for 20 cells. I tried out this formula
first:
{=STDEV((--($E$2:$E$296=K17))*$F$2:$F$296/1000000)}
Using it an array - the Ctrl+Shift+Enter thing. That didn't work out too
well.
Cells E2:E296 contained the Industry Code column. Cells F2:F296 contained
the market capitlisations, while K17 was one of the 20 industry codes.
I think the reason why it didn't work (apart from probably wrong usage of
the double negatives on my part) was that it produced zeros for the
companies
that I didn't want to include, which could screw up the STDEV calc, since
it
includes any zeros in the calculations.
Is there any way around this?
I thought there might be another way by using standard deviation = square
root (expected value of x^2 - (average of x)^2 ) but couldn't really
figure
out how to do a conditional squared sum. Is there of a way of doing that?
Thanks in advance,
Iwan J
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