80 Forecasting
Example: Econo-Wise Home Appliance Company had quarterly sales for the years 2000
thru 2002 as follows:
Sales (IN $K)
Quarterly 1st 2nd 3rd 4th
2000 397 376 460 501
2001 455 390 530 560
2002 513 434 562 593
Find the centered 4-quarter moving average and seasonal variation factor for each quarter.
12c platinum / 12C
RPN Keystrokes
12c platinum
ALG Keystrokes
Display Comments
fCLEARH fCLEARH
0.00
397?1 397?1
397.00
376?2 376?2
376.00
460?3 460?3
460.00
501?4 501?4
501.00
455?5 455?5
455.00
g(000t g(000t
440.75
Centered 4-element average for
3rd quarter, 2000.
t t
104.37
Seasonal variation factor.
390t 390t
449.75
4th quarter, 2000.
t t
111.40
530t 530t
460.25
1st quarter, 2001.
t t
98.86
560t 560t
476.38
2nd quarter, 2001.
t t
81.87
513t 513t
491.00
3rd quarter, 2001.
t t
107.94
434t 434t
503.75
4th quarter, 2001.
t t
111.17
562t 562t
513.25
1st quarter, 2002.
t t
99.95
593t 593t
521.38
2nd quarter, 2002.
t t
83.24
Now, what is the average of each quarter's seasonal variation for the two years?
12c platinum / 12C
RPN Keystrokes
12c platinum
ALG Keystrokes
Display Comments
fCLEAR² fCLEAR²
0.00
98.86_ 98.86_
1.00
99.95_ 99.95_
2.00
gÖ gÖ
99.41
1st quarter average seasonal
variation, %.