Following are percentages for annual sales growth and net sales attributed to loyalty card usage at 74 Noodles & Company restaurants.

(a) Make a scatter plot.

(b) Find the correlation coefficient and interpret it.

(c) Test the correlation coefficient for significance, clearly stating the degrees of freedom.

(d) Does it appear that loyalty card usage is associated with increased sales growth?

Noodles & Company Sales Growth and Loyalty Card Sales (n = 74 restaurants)

Growth% = annual sales growth (%)

Loyalty% = loyalty card % of net sales

Restaurant	Growth_Percent	Loyalty_Percent
1	-8.3	2.1
2	-4.0	2.5
3	-3.9	1.7
4	-3.4	2.1
5	-3.3	2.5
6	-1.9	3.0
7	-0.8	2.3
8	-0.4	2.3
9	-0.2	2.2
10	-0.2	2.3
11	0.5	2.1
12	0.6	2.5
13	0.8	2.0
14	1.9	2.0
15	2.0	2.0
16	2.1	2.6
17	2.8	2.2
18	2.9	2.1
19	4.0	1.9
20	4.0	2.2
21	4.0	0.7
22	4.0	2.0
23	4.2	1.8
24	4.6	2.1
25	5.1	2.5
26	5.1	2.6
27	5.5	2.0
28	5.9	2.0
29	5.9	1.4
30	6.0	2.0
31	6.1	2.1
32	6.1	2.1
33	6.1	2.7
34	6.3	2.0
35	6.6	2.0
36	6.9	1.6
37	6.9	1.9
38	7.1	1.6
39	7.4	1.8
40	7.7	2.2
41	7.9	2.2
42	8.1	2.8
43	8.3	2.4
44	8.5	3.1
45	8.6	2.2
46	8.7	1.3
47	8.8	1.8
48	8.8	2.5
49	8.9	1.9
50	9.1	2.0
51	9.5	2.4
52	10.2	2.2
53	10.7	2.2
54	11.0	0.3
55	11.3	1.9
56	11.4	1.9
57	11.5	2.2
58	11.7	2.6
59	11.8	2.2
60	11.9	2.1
61	12.5	2.0
62	12.8	0.9
63	13.8	1.1
64	14.1	3.4
65	14.2	1.2
66	14.6	2.1
67	14.9	0.9
68	15.4	2.2
69	16.2	1.7
70	17.2	2.4
71	18.4	2.8
72	20.8	1.1
73	25.5	0.6
74	28.8	1.8