HP 12c Solutions Handbook page 92

1. Key in the number 1 and press
2. Key in the selected and press
3. From the selection routing or from a previous forecast:
o Key in the smoothed average S
o Key in the trend T
o Key in the forecast
4. Key in the current data value and press
forecasting the value just entered.
5. Press
period.
6. Record the following values:
and
also wish to record
7. Repeat steps 4, 5, and 6 for the next forecast if available.
Example: Select the best smoothing constant based on sales (in
thousands of dollars) of 22, 23, 23, 25, 23, 27, 25. Given the current sales
in month 8 of 26, forecast the following month. Select the smoothing
constant ( ):
Keystrokes
CLEAR
1
.5 0
1
22 2
23 6
23
25
23
27
25
and press
t-1
t+1
. The displayed value represents the forecast for the next
6 (D ) for use as initial values in the next forecast. You may
t+1
5 (D
Display
0.00
1.00
0.50
0.50
22.00
0.00
23.00
23.25
25.25
23.69
27.13
25.95
.
0
and press
t-1
3.
and press
. The output is the error in
0 ( ),
).
t
91
1.
2.
6.
2 (S ), 3 (T
t-1
)
t-1