HP 12C manual Simple Moving Average, Gompertz Curve Trend Analysis, 155

Simple Moving Average

•X = moving average.

•m = number of elements in moving average.

	X	1	+ X	2	+ X	3	...x
							+ X	nmm
X1 =	------------------------------------------------------				m
								-

•

	X	1	+ X	2	+ X	3	...x		+ 1
							+ X	nmm
X2 =	----------------------------------------------------------------				m

•etc.

Seasonal Variation Factors Based on a Centered Moving Average

•Xc = centered moving average

•m = number of elements in the centered moving average.

	X1		+ X		+ X...		Xm + 1
	------ + (X
		2		3		MM
Xc = 2--------------------------------------------------------------------------------------					m		2

•SV = Seasonal variation factor.

•xi = value of the ith data point.

•i = centered moving average of the ith data point.

Xi

SV = ----

Xi

Gompertz Curve Trend Analysis

•y = ca(bx)

•where x, y, a, b, and c are positive.

•

1

--

 S3 – S2 n b =  -------------------

S2 – S1

(1 – a)

Dt = St + ----------------Tt

α

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