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At an outpatient clinic the management decided to take random samples comprising 8 ambulatory patients on each weekday for four weeks to study the patients waiting times and assess if the quality requirement for patient waiting times was met. The employees at the clinic were not aware of this investigation. The waiting time of each patient was recorded. A patient's waiting time is the period starting when the patient arrives at the clinic and ending when a technologist sees the patient. Thus 20 samples each comprising 8 randomly selected waiting times were recorded. Create Xbar-R chart and explain. Can you explain the special cause variation? The patient expectation is 20 minutes. Are there defects in the process?

Day	Obs 1	Obs 2	Obs 3	Obs 4	Obs 5	Obs 6	Obs 7	Obs 8
Monday	18.95	12.23	17.36	12.27	20.20	14.97	32.67	15.65
Tuesday	27.02	24.06	21.10	13.82	16.81	16.15	10.96	19.23
Wednesday	21.50	22.21	21.06	15.62	19.15	23.38	16.16	18.01
Thursday	21.56	18.89	14.89	18.17	18.23	17.09	13.68	19.26
Friday	21.77	13.68	28.24	19.90	11.39	28.21	14.53	17.74
Monday	14.31	8.49	13.23	13.84	19.86	13.52	14.16	10.55
Tuesday	13.84	8.15	13.43	21.31	10.29	14.31	7.22	9.58
Wednesday	7.34	9.79	10.68	15.54	18.83	15.91	18.87	11.64
Thursday	12.96	14.11	16.82	20.21	20.65	22.78	23.98	24.96
Friday	19.17	17.94	18.09	20.19	23.21	13.50	20.43	11.04
Monday	11.84	13.45	7.78	19.10	12.66	15.42	18.00	8.85
Tuesday	12.19	12.46	7.09	16.90	15.13	19.53	14.31	15.69
Wednesday	13.51	14.21	14.25	8.52	9.11	21.20	10.51	24.23
Thursday	9.99	12.52	13.39	14.78	13.78	16.86	16.92	14.75
Friday	18.97	19.52	21.23	21.08	13.78	20.36	25.87	23.63
Monday	12.97	14.28	11.31	15.77	25.88	13.30	15.88	20.23
Tuesday	10.20	14.01	6.73	10.75	14.42	7.37	12.26	18.59
Wednesday	10.16	14.83	11.60	11.96	13.80	15.50	16.06	13.49
Thursday	13.89	16.21	15.79	18.21	10.51	9.15	12.32	9.13
Friday	18.79	20.53	19.87	21.47	25.75	20.11	12.95	15.59