Reference no: EM13891624

Dry Goods Sales

The data is for weekly sales in the dry goods department at a Wal*Mart store in the Northeast.

I.e. spikes, usually occur at holiday periods. Week 1 is the first week of February 2003. To s week 1 of 2004 is represented as week 53 since week 53 represents the start of the 2004 fisc values are adjusted in order to disguise true sales figures, but trends in the data are retained fo purposes. Note that for 2002­2003 data, Wal*Mart used 53 weeks for their fiscal year data.

Week	Sales in $
41	18000
42	16800
43	15200
44	15000
45	13600
46	16000
47	12600
48	14800
49	16800
50	14800
51	15200
52	16000
53	15600
54	15600
55	15000
56	15700
57	15800
58	13800
59	12800
60	14400
61	15800
62	16000
63	12400
64	16200
65	17000
66	18600
67	16000
68	18000
69	19600
70	18600
71	18450
72	18000
73	18200
74	18600
75	16000
76	15200
77	16800
78	15800
79	17600
80	15800
81	15600
82	14200
83	16600
84	16100
85	14100
86	14400
87	14500
88	16900
89	17000
90	16000
91	17800

Dry Goods 2003-2004

1. Can you identify holiday periods or special events that cause the spikes in the data?

2. What holiday results in the maximum sales for this department?

3. a) Generate linear and quadratic models for this data.

b) What is the marginal sales for this department using each model.

c) Which model do you feel best predicts future trends and explain your rational.

4. Based on the model selected, what type of seasonal adjustments, if any, would be required to meet customer needs?

5. Some items were added or subtracted from the 2003-2004 dry goods department data when compared with the data available for the previous year (2002-2003).

a) Use your best model for the 2003-2004 data set to predict sales for the next four weeks. Provide chart and model backup for predictions.

b) Compute the percent rate of increase (y₂-y₁) / y₁ for the next four weeks using results from part a). Provide appropriate backup material.

c) Using 2002-2003 data, find the percentage rate of increase for the next four weeks. Provide chart, model and computation backup. Note and discuss differences in part b) and part c) results.