HP 12C Financial 12C Statistics, Weighted Mean, Linear Estimation, Standard Deviation, Factorial

Appendix E: Formulas Used 257

Statistics

Mean			= ∑ y
x	= ∑ x	y
	n		n

Weighted Mean

xw = ∑wx

∑w

Linear Estimation

n = number of data pairs

yˆ = A + Bx

xˆ =

y − A

B

∑ xy − ∑ x ⋅ ∑ y

where B =

n

∑ x2 −

(∑ x )2

A =

y

− Bx

n

⎡

∑ x ⋅∑ y ⎤

⎢∑ xy

−

n

⎥

r =

⎣

⎦

⎡

2

⎤

⎡

2

⎤

⎢∑ x 2

−

(∑ x )

⎥ ⋅

⎢∑ y 2

−

(∑ y )

⎥

n

⎢

n

⎥

⎢

⎥

⎣

⎦

⎣

⎦

Standard Deviation

sx = n∑ x 2 − (∑ x )2

sy =

n∑ y 2 − (∑ y )2

n(n − 1)

n(n − 1)

Factorial

0! = 1

For n > 1 where n is an integer:

n

n!= ∏i

i=1

File name: hp 12c pt_user's guide_English_HDPMF123E27	Page: 257 of 275
Printed Date: 2005/8/1	Dimension: 14.8 cm x 21 cm