- #1
vokurka
- 4
- 0
In my lab I measure some chemical data. Output from the software I use contain also some stats, like the mean value, standard deviation and some number called SIGMA MEAN. My typical dataset looks like this:
sample MgO Al2O3
a 5,307872109 7,45113642
b 8,496074587 9,182072932
c 1,413995015 7,488017765
d 5,241196501 12,15347965
e 1,592772949 7,863316958
f 0,518347063 4,050451192
g 1,117824945 5,952661741
Mean value: 3,384011881 7,734448094
Sigma: 2,992231593 2,53402361
Sigma mean: 1,130957237 0,957770898
I know what is mean value and standard deviation sigma, but I never heard about sigma mean. It is always smaller than sigma and it seems to depend on sigma. Please do somebody know what it is Sigma mean?
sample MgO Al2O3
a 5,307872109 7,45113642
b 8,496074587 9,182072932
c 1,413995015 7,488017765
d 5,241196501 12,15347965
e 1,592772949 7,863316958
f 0,518347063 4,050451192
g 1,117824945 5,952661741
Mean value: 3,384011881 7,734448094
Sigma: 2,992231593 2,53402361
Sigma mean: 1,130957237 0,957770898
I know what is mean value and standard deviation sigma, but I never heard about sigma mean. It is always smaller than sigma and it seems to depend on sigma. Please do somebody know what it is Sigma mean?