WalMart’s fiscal year starts the first week of February. This means that when analyzing the data, week 26 is actually week 30 (26+4 weeks for January) in 2002 or the end of July 2002. Also, week 52 is actually week 4 (52+4 weeks for January 2002 minus 52 weeks for 2002) in 2003 or the end of January 2003. As an example, the spike in sales (revenue) at week 75 occurs in week 27 (75+4 weeks for January 2002 minus 52 weeks for 2002) in 2003 or the first week in July 2003. This corresponds to sales for the July 4th holiday when people are buying barbecue related items. When doing your least squares modeling of the data, don’t forget to generate the model (linear or quadratic) and then remove outliers (extreme values causing spikes in the data) and rerun the model. The results should improve with better R2 values. Discuss what outliers were removed and why.
Week | Sales in $ |
26 | 15200 |
27 | 15600 |
28 | 16400 |
29 | 15600 |
30 | 14200 |
31 | 14400 |
32 | 16400 |
33 | 15200 |
34 | 14400 |
35 | 13800 |
36 | 15000 |
37 | 14100 |
38 | 14400 |
39 | 14000 |
40 | 15600 |
41 | 15000 |
42 | 14400 |
43 | 17800 |
44 | 15000 |
45 | 15200 |
46 | 15800 |
47 | 18600 |
48 | 15400 |
49 | 15500 |
50 | 16800 |
51 | 18700 |
52 | 21400 |
53 | 20900 |
54 | 18800 |
55 | 22400 |
56 | 19400 |
57 | 20000 |
58 | 18100 |
59 | 18000 |
60 | 19600 |
61 | 19000 |
62 | 19200 |
63 | 18000 |
64 | 17600 |
65 | 17200 |
66 | 19800 |
67 | 19600 |
68 | 19600 |
69 | 20000 |
70 | 20800 |
71 | 22800 |
72 | 23000 |
73 | 20800 |
74 | 25000 |
75 | 30600 |
76 | 24000 |
77 | 21200 |
Generate supporting Excel graphs using scatter plots
1. Identify spikes (outliers) in the data where extreme sales values occur and correlate these spikes with actual calendar dates in 2002 or 2003 and with holidays or special events that may occur during these periods.
2. Modeling the data linearly -
a. Generate a linear model for this data by choosing two points.
b. Generate a least squares linear regression model for this data.
c. How good is this regression model? Output and discuss the R2 value.
d. What are the marginal sales (derivative, i.e. rate of change) for this department using the linear model with two data points and the regression model?
e. Compare the two models. Which do you feel is better? f. Remove appropriate outliers as you deem necessary and rerun the linear regression model. What is the marginal sales and discuss improvements.
3. Modeling the data quadratically -
a. Generate a quadratic model for this data. Also output and discuss the R2 value.
b. What are the marginal sales for this department using this model?
c. Calculate the model generated relative max/min value. Show backup analytical work.
d. Compare actual and model generated relative max/min value.
e. Remove outliers and rerun the quadratic least squares model. What is the marginal sales and discuss improvements.
4. Comparing models
a. Based on all models run, which model do you feel best predicts future trends? Explain your rationale.
b. Based on the model selected, what type of seasonal adjustments, if any, would be required to meet customer needs?
WalMart’s fiscal year starts the first week of February. This means that when analyzing the data,...
The WalMart’s fiscal year starts the first week of February. This means that when analyzing the data, week 26 is actually week 30 (26+4 weeks for January) in 2002 or the end of July 2002. Also, week 52 is actually week 4 (52+4 weeks for January 2002 minus 52 weeks for 2002) in 2003 or the end of January 2003. As an example, the spike in sales (revenue) at week 75 occurs in week 27 (75+4 weeks for January 2002...
The WalMart’s fiscal year starts the first week of February. This means that when analyzing the data, week 26 is actually week 30 (26+4 weeks for January) in 2002 or the end of July 2002. Also, week 52 is actually week 4 (52+4 weeks for January 2002 minus 52 weeks for 2002) in 2003 or the end of January 2003. As an example, the spike in sales (revenue) at week 75 occurs in week 27 (75+4 weeks for January 2002...
Note that WalMart’s fiscal year starts the first week of February. This means that when analyzing the data, week 26 is actually week 30 (26+4 weeks for January) in 2002 or the end of July 2002. Also, week 52 is actually week 4 (52+4 weeks for January 2002 minus 52 weeks for 2002) in 2003 or the end of January 2003. Outliers (extreme values) are present in the data and can distort modeling results. As an example, spikes in sales...
Note that WalMart’s fiscalyear starts the first week of February. This means that when analyzing the data, week 26 is actuallyweek 30 (26+4 weeks for January) in 2002 or the end of July 2002. Also, week 52 is actually week 4(52+4 weeks for January 2002 minus 52 weeks for 2002) in 2003 or the end of January 2003. Outliers(extreme values) are present in the data and can distort modeling results. As an example, spikes in sales(revenue) at weeks 28-30 occurs...
Week Sales 26 15200 27 15600 28 16400 29 15600 30 14200 31 14400 32 16400 33 15200 34 14400 35 13800 36 15000 37 14100 38 14400 39 14000 40 15600 41 15000 42 14400 43 17800 44 15000 45 15200 46 15800 47 18600 48 15400 49 15500 50 16800 51 18700 52 21400 53 20900 54 18800 55 22400 56 19400 57 20000 58 18100 59 18000 60 19600 61 19000 62 19200 63 18000 64 17600...
Project #2Wal*Mart Dry Goods Sales 2003-2004The following items are a guide for responses to be addressed in project two. Note that WalMart’s fiscal year starts the first week of February. This means that when analyzing the data, week 41 is actually week 45 (41+4 weeks for January) in 2003 or the beginning of November 2003. Also, week 52 is actually week 4 (52+4 weeks for January 2003 minus 52 weeks for 2003) in 2004 or the end of January 2004. ...
the first two are the instructions to the assignment and the last two are the data MATH.1220 Management Calculus Project #1 Wal Mart Dry Goods Sales 2002-2003 The following items are a guide for responses to be addressed in project one. Note that WalMart's fiscal year starts the first week of February. This means that when analyzing the data, week 26 s actually week 30 (26+4 weeks for January) in 2002 or the end of July 2002. Also, week 52...