In: Statistics and Probability
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.
1. Identify spikes(outliers) in the data where extreme (high or low) sales values occur and correlate these spikes with actual calendar dates in 2003 or 2004 and with any holidays or special events or abnormally slow periods that may occur during these periods.
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 |
That's an interesting question. Let's plot the data on a graph and let us see what we get:
Well the graph's present an interesting enough picture.
Here are the snapshot of the calender in 2003
So we had really high sales during the holiday season, like Christmas, Easter, memorial day, labor day etc which is to be anticipated as people spend more when they have the time and holidays to, while the sales really hit it tough during the summers, in months of July end, September or even in April. This is expected too.
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