- Data Penjualan
UD.
TEH POCI
DATA
PENJUALAN TEH POCI
BULAN
|
Y
|
X
|
XY
|
X2
|
X4
|
X2Y
|
JANUARI
|
900
|
-9
|
-8100
|
81
|
6561
|
72900
|
FEBRUARI
|
990
|
-7
|
-6930
|
49
|
2401
|
48510
|
MARET
|
1000
|
-5
|
-5000
|
25
|
625
|
25000
|
APRIL
|
1200
|
-3
|
-3600
|
9
|
81
|
10800
|
MEI
|
815
|
-1
|
-815
|
1
|
1
|
815
|
JUNI
|
430
|
1
|
430
|
1
|
1
|
430
|
JULI
|
560
|
3
|
1680
|
9
|
81
|
5040
|
AGUSTUS
|
959
|
5
|
4795
|
25
|
625
|
23975
|
SEPTEMBER
|
1100
|
7
|
7700
|
49
|
2401
|
53900
|
OKTOBER
|
1000
|
9
|
9000
|
81
|
6561
|
81000
|
∑
|
8954
|
0
|
-840
|
330
|
19338
|
322370
|
n =
10, dengan syarat ∑x= 0
Persamaan Trend
GarisLengkung
Y = a + bx + c.(x)2
a. Mencarinilai
a dan c
∑y
= n . a + c . ∑x2
∑x2y
= ∑x2. a + c . ∑x4
8954 = 10.a + c.330 (x33) 295482 = 330 . a + c . 10890
322370 = 330.a + c.19338 ( x1 ) 322370 = 330 . a + c . 19338
-26888 : -8448 = c
3,18 = c
8954
= 10 . a + c . 330
8954
= 10 . a + (3,18) . 330
8954
= 10 a + 1409,4
8954
– 1409,4 = 10 a
7904,6
= 10a
790,46 = a
b. mencari nilai b
b = ∑xy : ∑x2
= -840 : 330
= -2,54
2. Ramalan penjualan untukbulan November
2016 – April 2017
November 2016: Y = a +
bx + c (x)2
= 790,46 + (-2,94).11 + 3,18 (11)2
=
790,46 + (-32,34) + 384,78
= 1142,9 = 1143 cup
Desember2016 : Y = a + bx + c (x)2
=
790,46 + (-2,94).13 + 3,18 (13)2
=
790,46 + (-38,22) + 537,42
=
1289,66 = 1290 cup
Januari2107 : Y
= a + bx + c (x)2
=790,46 + (-2,94).15 + 3,18 (15)2
=
790,46 + (-44,1) + 715,5
= 1461,86 = 1462 cup
Februari2017 : Y = a + bx + c (x)2
= 790,46 + (-2,94).17 + 3,18 (17)2
= 790,46 + (-49,98) + 919,02
= 1659,5 = 1660 cup
Maret2107 : Y
= a + bx + c (x)2
= 790,46 + (-2,94).19 + 3,18 (19)2
= 790,46 + (-55,86) + 1147,98
= 1882,58 = 1883 cup
April 2017 : Y
= a + bx + c (x)2
= 790,46 + (-2,94).21 + 3,18 (21)2
= 790,46 + (-61,74) + 1402,38
=
2131.1 = 2131 cup
3.
Grafik Trend Garis Lengkung
