HP 12c Platinum - Forecasting with Exponential Smoothing; Pricing Calculations; Markup and Margin Calculations

Appendix B 161
()
1
1
lnlnln
1
1
−
−
+==
∑
=
b
b
abcnyS
n
n
i
i
()
1
1
lnlnln
2
1
1
2
−
−
+==
∑
+=
+
b
b
abcnyS
n
n
ni
n
i
()
1
1
lnlnln
3
12
12
3
−
−
+==
∑
+=
+
b
b
abcnyS
n
n
ni
n
i
a, b and c are determined by solving the three equations above simultaneously.
Forecasting With Exponential Smoothing
α = smoothing constant (0 < α < 1)
X
t
= actual current period usage
1
α1α average, Smoothed
−
)
−
(
+
=
ttt
SX S
1
Change,
t - tt
- S S C
=
1
α1α Trend,
−
)
−
(
+
=
ttt
ΤΧ T
Current period expected usage,
()
ttt
TSD
α
α1−
+=
Forecast of next period expected usage,
ttt
TSD






+=
+
α
1
ˆ
1
Error,
ttt
XDe −=
ˆ
Cumulative error
∑
=
=
m
t
t
e
1
2
0 and :conditions Initial
111
=
=
−−− ttt
TXS
Pricing Calculations
Markup and Margin Calculations
Ma = margin(%).
Mu = markup(%).
S = selling price.
C = cost.
S
CS
Ma
−
=100
C
CS
Mu
−
=100