262 Appendix E: Formulas Used
Statistics
Mean
∑
x
x
y
=
=
n
Weighted Mean
∑
wx
x
=
w
∑
w
Linear Estimation
n = number of data pairs
ˆ
y
A
Bx
=
+
y
A
−
ˆ
x
=
B
∑
xy
B
=
where
∑
x
A
y
B
x
=
−
⎡
∑
⎢
⎣
r
=
(
⎡
∑
2
∑
x
−
⎢
⎢
⎣
Standard Deviation
2
∑
n
x
−
s
=
x
n
(
n
−
Factorial
0! = 1
For n > 1 where n is an integer:
n
n
!
∏
i
=
i
1
=
∑
y
n
∑
∑
x
y
⋅
−
n
(
)
2
∑
x
2
−
n
∑
∑
x
y
⋅
⎤
xy
−
⎥
n
⎦
(
)
⎡
2
⎤
∑
x
2
∑
y
⋅
−
⎥
⎢
n
⎥
⎢
⎦
⎣
(
)
2
∑
∑
x
n
s
=
y
) 1
)
2
⎤
y
⎥
n
⎥
⎦
(
)
2
2
∑
y
y
−
n
(
n
) 1
−