Artel PCS 2 - Formulas Used to Calculate Group Statistics

15A2135L
APPENDIX C
FORMULAS USED TO CALCULATE GROUP STATISTICS
Mean
n
x
x
n
i
i
∑
=
=
1
Standard Deviation
()
1
1
2
−
−
=
∑
=
n
xx
STD
n
i
i
Coefficient of Variation
% 100×=
x
STD
CV
Inaccuracy
(
)
100
volumenominal
volumenominal
×
−
=
x
INACC
Combined Expanded
Uncertainty of the mean,
k =2
()
⎟
⎠
⎞
⎜
⎝
⎛
×
+×=
n
STD
x
u
i
U
2
2
2
Standard Relative Uncertainties for PCS
Ranges 1 through 6:
u
1
=0.5% u
4
=0.3%
u
2
=0.4% u
5
=0.3%
u
3
=0.3% u
6
=0.3%
(n is the number of data points)