114
b
t
=
?
(S
t
-
S
(t -1)
)
+
(1 -
?
)b
(t -1)
b2
=
?
(S
2
-
S1 ) + (1 -
?
)b1
= 0.1 * (25 - 22) + (1 – 0.1).(3) = 3
-
Peramalan periode ke-3
S
t
=
a
*
X
t
+
(1 -
a
)(S
(t -1)
+
b
(t -1)
)
S3
=
a
*
X
3
+
(1 -
a (S
)(S
2
+
b2 )
= 0.7 * 36 + (1 – 0.7).(25 + 3) = 33.60
b
t
=
?
(S
t
-
S
(t -1)
)
+
(1 -
?
)b
(t -1)
b3
=
?
(S3 - S
2
)
+
(1 -
?
)b2
= 0.1 (33.60- 25) + (1 – 0.1).(3) = 3.56
F
(t +m
)
=
S
t
+
b
t
*
m
Pada periode 3, m = 1.
F3
=
S
2
+
b2
*
m
= 25 + 3 * 1 = 28
e
t
=
X
t
-
F
t
e3
=
X
3
-
F3
=
36 – 28 = 8
|e3| = 8
 |