AlphaCo takes customer service seriously. Recently the operations department has been pushing for a proposal to increase the investment in finished product inventory to improve after sales service. The argument is that with a higher level of available finished products, the operations department can easily do replacement for faulty products and thus improve after sales service. However, investment in inventory should be considered cautiously as capital tied up in inventory normally generates lower return than investment in other assets. AlphaCo's management wants to find out if the operations department's hypothesis can be supported by the collected data. You are tasked to perform an association analysis according to the following requirements.

(i) Use an appropriate chart type to examine the relationship between the two variables. Provide a brief justification of your choice. What can you observe and conclude from the chart? (ii) Use an appropriate statistical tool to examine the relationship between the two variables. Clearly present the steps and components of the tool (if any), as well as the result of analysis. What can be concluded from the analysis? Is the conclusion consistent with the observations and conclusions in (b)(i)? (iii) Is it possible to establish a causality between inventory level and after sales service, i.e., increase in inventory level improves/deteriorates after sales service, based on the conclusion in (b)(i) and (b)(ii)?

Data:

Week	Inventory (units)	Complaint (cases)
1	3221	37
2	3236	40
3	3279	45
4	3400	43
5	3409	39
6	3426	39
7	3374	51
8	3214	43
9	3345	43
10	3554	45
11	3731	59
12	3836	57
13	4209	41
14	4190	51
15	4259	49
16	4266	52
17	4271	46
18	4194	48
19	4095	45
20	3904	47
21	3791	46
22	3746	43
23	3899	45
24	4190	44
25	4539	41
26	4586	45
27	4541	49
28	4524	55
29	4505	54
30	4464	54
31	4251	51
32	3896	48
33	3659	44
34	3570	42
35	3839	40
36	4106	38
37	4491	33
38	4424	39
39	4385	41
40	4404	49
41	4361	49
42	4286	48
43	3999	45
44	3740	41
45	3389	40
46	3336	37
47	3581	37
48	3944	35
49	4185	32
50	4084	35
51	4071	37
52	4086	38
53	4129	39
54	3910	40
55	3539	39
56	3406	38
57	3181	37
58	3204	35
59	3365	34
60	3524	33