Mitsumishi is a Korean company whose number of light trucks sold between January
ID: 421982 • Letter: M
Question
Mitsumishi is a Korean company whose number of light trucks sold between January 2000 and June 2003 is reported in Table 2.31.
The company usually carries out a promotion in May and/or in June. The sales improvement achieved during the last few promotions are shown in Table 2.32.
Table 2.32 Light trucks sales improvement of Mitsumishi.
Period Sales improvement (%)
May 2000 +30
May 2001 +20
June 2001 +15
May 2002 +25
June 2003 +30
Table 2.33 Sales of the new spiced food (in hundreds of kilograms)
produced by Mare Nostrum.
Year
Month 2001 2002 2003
January 130 000 141 988 156 467
February 129 720 142 376 158 137
March 129 703 143 636 159 140
April 129 633 144 543 161 156
May 129 632 147 534 162 835
June 129 854 148 919 165 479
July 130 436 150 961
August 132 751 152 748
September 133 334 152 977
October 133 761 154 387
November 135 286 156 856
December 136 800 157 349
(a) Using a classical decomposition method, forecast the sales for the next
six months.
(b) Plot a control chart of the error over the last three months. Are you able
to detect any anomaly?
Explanation / Answer
a. may=2030,2021,2027
june=2016,2033
av 6 months=2030+2021+2027=6087/3
av 6 months=4099/2=2045
(B)no anamolies detected