Weighted Mean; Linear Estimation; Standard Deviation; Factorial - HP 12C Platinum Owner's Handbook Manual

192 Appendix : Formulas Used

Weighted Mean

∑
wx
x = ------------- -
w
∑
w

Linear Estimation

n = number of data pairs
y ˆ = A + Bx
y A –
x ˆ = ----------- -
B
∑
∑
xy – ----------------------- -
where B =
------------------------------------------ -
∑
(
2
∑
x – ---------------- -
A = y Bx –
∑
xy –
r = -------------------------------------------------------------------------------------------
∑
( )
x
2
∑
x – ---------------- -
n

Standard Deviation

2
∑ ∑
(
n x – x
s = -------------------------------------- -
x ( )
n n 1 –

Factorial

0! = 1
For n > 1 where n is an integer:
∑
⋅
x y
n
2
)
x
2
∑ ∑
⋅
x y
----------------------- -
n
2 2
∑
( )
y
2
∑
⋅
y – ---------------- -
n
2
2
∑ ∑
) (
n y – y
s = -------------------------------------- -
y ( )
n n 1 –
2
)