Refer to the data file P08_66.xlsx. Comfy Company sells mediumpriced patio furniture through a mail-order catalog. It has operated primarily in the East but is now expanding to the Southwest. To get off to a good start, it plans to send potential customers a catalog with a discount coupon. However, Comfy is not sure how large a discount is needed to entice customers to buy. It experiments by sending catalogs to selected residents in six cities. Tucson and San Diego receive coupons for 5% off any furniture within the next two months, Phoenix and Santa Fe receive coupons for 10% off, and Riverside and Albuquerque receive coupons for 15% off.

Comfy wonders whether there are differences across pairs of cities that receive the same discount.

a. Calculate a 95% confidence interval for the difference between the mean amount spent for the following pairs of cities: (These means should include the "0 purchases." Round your answers to one decimal place, if necessary. If your answer is negative number, enter "minus" sign.)

	Lower Limit	Upper Limit
Tucson minus San Diego
Phoenix minus Santa Fe
Riverside minus Albuquerque

Does city appear to make a difference?

SelectYesNo

b. Calculate a 95% confidence interval for the difference between the proportion of customers who purchase something for the following pairs of cities: (Round your answers to three decimal places, if necessary. If your answer is negative number, enter "minus" sign.)

	Lower Limit	Upper Limit
Tucson minus San Diego
Phoenix minus Santa Fe
Riverside minus Albuquerque

Does city appear to make a difference?

SelectYesNo

Customer	City	Discount	Items Purchased	Total Paid
1	Tucson	5%	0	0
2	Tucson	5%	1	409
3	Tucson	5%	0	0
4	Tucson	5%	1	395
5	Tucson	5%	0	0
6	Tucson	5%	0	0
7	Tucson	5%	1	229
8	Tucson	5%	1	340
9	Tucson	5%	0	0
10	Tucson	5%	1	294
11	Tucson	5%	0	0
12	Tucson	5%	0	0
13	Tucson	5%	0	0
14	Tucson	5%	1	325
15	Tucson	5%	1	381
16	Tucson	5%	0	0
17	Tucson	5%	0	0
18	Tucson	5%	0	0
19	Tucson	5%	0	0
20	Tucson	5%	0	0
21	Tucson	5%	0	0
22	SanDiego	5%	0	0
23	SanDiego	5%	1	602
24	SanDiego	5%	1	516
25	SanDiego	5%	0	0
26	SanDiego	5%	1	591
27	SanDiego	5%	0	0
28	SanDiego	5%	0	0
29	SanDiego	5%	0	0
30	SanDiego	5%	1	643
31	SanDiego	5%	1	523
32	SanDiego	5%	0	0
33	SanDiego	5%	0	0
34	SanDiego	5%	1	468
35	SanDiego	5%	0	0
36	SanDiego	5%	0	0
37	SanDiego	5%	0	0
38	SanDiego	5%	0	0
39	SanDiego	5%	0	0
40	SanDiego	5%	1	595
41	SanDiego	5%	0	0
42	SanDiego	5%	0	0
43	SanDiego	5%	0	0
44	SanDiego	5%	0	0
45	SanDiego	5%	0	0
46	SanDiego	5%	1	562
47	Phoenix	10%	1	365
48	Phoenix	10%	1	350
49	Phoenix	10%	0	0
50	Phoenix	10%	0	0
51	Phoenix	10%	0	0
52	Phoenix	10%	0	0
53	Phoenix	10%	0	0
54	Phoenix	10%	1	333
55	Phoenix	10%	1	338
56	Phoenix	10%	2	568
57	Phoenix	10%	0	0
58	Phoenix	10%	1	369
59	Phoenix	10%	0	0
60	Phoenix	10%	1	360
61	Phoenix	10%	1	326
62	Phoenix	10%	2	523
63	Phoenix	10%	2	530
64	Phoenix	10%	0	0
65	Phoenix	10%	0	0
66	Phoenix	10%	1	338
67	Phoenix	10%	1	305
68	Phoenix	10%	2	664
69	Phoenix	10%	2	461
70	Phoenix	10%	0	0
71	Phoenix	10%	1	395
72	Phoenix	10%	1	284
73	Phoenix	10%	0	0
74	Phoenix	10%	0	0
75	Phoenix	10%	2	568
76	Phoenix	10%	1	260
77	Phoenix	10%	0	0
78	SantaFe	10%	1	307
79	SantaFe	10%	1	397
80	SantaFe	10%	0	0
81	SantaFe	10%	0	0
82	SantaFe	10%	1	337
83	SantaFe	10%	0	0
84	SantaFe	10%	2	661
85	SantaFe	10%	0	0
86	SantaFe	10%	0	0
87	SantaFe	10%	1	368
88	SantaFe	10%	1	408
89	SantaFe	10%	0	0
90	SantaFe	10%	1	392
91	SantaFe	10%	2	814
92	SantaFe	10%	1	386
93	SantaFe	10%	0	0
94	SantaFe	10%	1	387
95	SantaFe	10%	1	310
96	SantaFe	10%	0	0
97	Riverside	15%	0	0
98	Riverside	15%	0	0
99	Riverside	15%	0	0
100	Riverside	15%	2	1024
101	Riverside	15%	1	451
102	Riverside	15%	1	433
103	Riverside	15%	0	0
104	Riverside	15%	0	0
105	Riverside	15%	1	436
106	Riverside	15%	2	854
107	Riverside	15%	1	496
108	Riverside	15%	0	0
109	Riverside	15%	1	422
110	Riverside	15%	0	0
111	Riverside	15%	0	0
112	Riverside	15%	1	398
113	Riverside	15%	1	409
114	Riverside	15%	1	551
115	Riverside	15%	1	458
116	Riverside	15%	1	520
117	Riverside	15%	2	788
118	Riverside	15%	1	373
119	Riverside	15%	0	0
120	Riverside	15%	0	0
121	Riverside	15%	1	367
122	Albuquerque	15%	2	412
123	Albuquerque	15%	1	253
124	Albuquerque	15%	0	0
125	Albuquerque	15%	1	200
126	Albuquerque	15%	0	0
127	Albuquerque	15%	0	0
128	Albuquerque	15%	2	648
129	Albuquerque	15%	2	315
130	Albuquerque	15%	1	264
131	Albuquerque	15%	1	234
132	Albuquerque	15%	1	260
133	Albuquerque	15%	2	632
134	Albuquerque	15%	2	587
135	Albuquerque	15%	0	0
136	Albuquerque	15%	1	210
137	Albuquerque	15%	1	298
138	Albuquerque	15%	1	244
139	Albuquerque	15%	1	284
140	Albuquerque	15%	1	239
141	Albuquerque	15%	1	201