Practice Exercise

*** Answer the followings

13.1 The following table provides data on the number of items damaged in shipment during 2001 - 2014 for a manufacturer.

Year Item
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
 533
373
132
555
168
281
175
291
228
204
349
234
209
176

13.2 The following table shows the sales volume (in thousands of dollars) of a retail store between 2001-2014.

Year Sales
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
 815
1276
4752
7535
10122
9642
14100
12529
12824
13777
15379
18705
17632
16571

13.3 The following table shows the number of items repaired during a company's warranty period between 2001 and 2014.

Year Items
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
 749
709
700
678
611
641
631
611
600
574
559
543
534
524

13.4 The following table shows the annual sales (unit: billion $) of a company for 11 years.

Year Sales
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
 12
14
18
20
18
16
20
22
27
24
30

13.5 The following data show the price of silver and crude oil between 2000 and 2015, respectively. Find the percentage change of silver and crude oil and the price indices and overlay them on one picture.

Year Silver
($/ounce)		 Crude Oil
($/barrel)
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
 1.771
1.546
1.684
2.558
4.708
4.419
4.353
4.620
5.440
11.090
20.633
10.481
7.950
11.439
8.141
6.192
 1.80
2.18
2.48
5.18
10.46
11.51
11.51
12.70
15.40
18.00
28.00
32.00
34.00
30.00
26.00
26.00

13.6 The following table shows the number of skis sold by a sports merchandise seller in 2017-2021. 1) Predict the next year with a multiplicative seasonal model. 2) Predict the next year using the Holt-Winters seasonal model.

Year.Month Sales
2017.1
2017.2
2017.3
2017.4
2017.5
2017.6
2017.7
2017.8
2017.9
2017.10
2017.11
2017.12
2018.1
2018.2
2018.3
2018.4
2018.5
2018.6
2018.7
2018.8
2018.9
2018.10
2018.11
2018.12
2019.1
2019.2
2019.3
2019.4
2019.5
2019.6
2019.7
2019.8
2019.9
2019.10
2019.11
2019.12
2020.1
2020.2
2020.3
2020.4
2020.5
2020.6
2020.7
2020.8
2020.9
2020.10
2020.11
2020.12
2021.1
2021.2
2021.3
2021.4
2021.5
2021.6
2021.7
2021.8
2021.9
2021.10
2021.11
2021.12
 0
2
10
4
89
33
11
4
17
5
17
0
3
0
5
4
14
23
7
11
11
4
4
8
9
2
46
11
14
30
22
4
7
4
0
2
13
4
56
30
90
20
15
11
6
5
1
7
4
12
6
10
17
32
24
9
10
5
17
1