The manager of a local fast-food restaurant is inter-ested in improving the service provided to customers who use the restaurant's drive-up window. As a first step in this process, the manager asks an assistant to record the time (in seconds) it takes to serve a large number of customers at the final window in the facil-ity's drive-up system. The file contains a random sample of 200 service times during the busiest hour of the day.

1. Identify the relevant population.
2. Construct and interpret a 95% confidence interval for the mean service time of all customers arriving during the busiest hour of the day at this fast-food operation.
3. If the manager wants to improve service, at least during the busiest time of day, does this confidence interval provide useful information? What useful information does it not provide?

Customer	Time in seconds	at least 120 sec?
1	138.6	1
2	43.3	0
3	57.5	0
4	84.2	0
5	44.7	0
6	30.4	0
7	317.6	1
8	82.4	0
9	67.0	0
10	84.6	0
11	71.0	0
12	39.2	0
13	68.7	0
14	40.2	0
15	44.2	0
16	73.0	0
17	37.7	0
18	54.4	0
19	94.4	0
20	38.8	0
21	129.5	1
22	51.1	0
23	45.6	0
24	114.5	0
25	91.3	0
26	94.8	0
27	94.7	0
28	102.3	0
29	31.1	0
30	40.0	0
31	38.8	0
32	90.9	0
33	32.1	0
34	35.6	0
35	198.5	1
36	96.6	0
37	115.2	0
38	110.7	0
39	181.6	1
40	60.6	0
41	143.5	1
42	50.3	0
43	111.9	0
44	79.1	0
45	65.9	0
46	178.1	1
47	96.2	0
48	38.4	0
49	141.0	1
50	63.0	0
51	47.2	0
52	44.5	0
53	248.8	1
54	34.5	0
55	44.8	0
56	30.9	0
57	133.4	1
58	41.2	0
59	34.8	0
60	30.7	0
61	269.5	1
62	64.3	0
63	171.8	1
64	51.2	0
65	117.5	0
66	41.6	0
67	96.7	0
68	58.6	0
69	49.1	0
70	58.2	0
71	43.1	0
72	134.1	1
73	149.8	1
74	120.5	1
75	32.2	0
76	128.3	1
77	113.7	0
78	154.9	1
79	68.0	0
80	52.5	0
81	63.5	0
82	40.7	0
83	164.9	1
84	211.1	1
85	225.8	1
86	162.0	1
87	163.5	1
88	79.3	0
89	52.5	0
90	84.6	0
91	72.2	0
92	69.8	0
93	89.3	0
94	365.4	1
95	35.9	0
96	96.9	0
97	62.4	0
98	79.5	0
99	152.0	1
100	212.1	1
101	152.8	1
102	87.6	0
103	188.4	1
104	67.0	0
105	122.8	1
106	158.1	1
107	138.9	1
108	155.0	1
109	91.6	0
110	194.2	1
111	74.8	0
112	269.4	1
113	30.4	0
114	112.0	0
115	67.3	0
116	210.2	1
117	97.6	0
118	71.5	0
119	39.3	0
120	30.7	0
121	68.5	0
122	45.0	0
123	132.6	1
124	91.2	0
125	60.1	0
126	90.6	0
127	81.2	0
128	58.2	0
129	40.9	0
130	46.8	0
131	45.5	0
132	88.6	0
133	40.0	0
134	165.7	1
135	56.7	0
136	49.8	0
137	230.4	1
138	41.5	0
139	70.6	0
140	37.2	0
141	107.1	0
142	75.2	0
143	197.8	1
144	50.2	0
145	77.1	0
146	85.6	0
147	167.9	1
148	86.5	0
149	40.5	0
150	66.0	0
151	46.7	0
152	49.9	0
153	175.1	1
154	193.7	1
155	34.1	0
156	119.5	0
157	72.3	0
158	183.8	1
159	31.1	0
160	166.9	1
161	126.9	1
162	190.1	1
163	120.0	1
164	38.3	0
165	35.2	0
166	100.4	0
167	70.8	0
168	102.3	0
169	101.7	0
170	54.9	0
171	123.5	1
172	43.8	0
173	66.4	0
174	38.0	0
175	144.4	1
176	37.6	0
177	68.3	0
178	88.8	0
179	132.3	1
180	112.4	0
181	52.5	0
182	42.7	0
183	85.0	0
184	92.7	0
185	90.8	0
186	256.0	1
187	50.0	0
188	226.1	1
189	113.8	0
190	41.1	0
191	77.1	0
192	517.7	1
193	112.0	0
194	76.3	0
195	73.2	0
196	88.4	0
197	198.4	1
198	36.9	0
199	47.6	0
200	50.7	0