The quality manager of a computer services company wants to create a specification for the amount of time it takes the company to respond to problems reported by customers. The goal time limits is 10 hours (i.e., 600 minutes) at most. To determine how well the company meets the specification, data are collected on the response times over recent weeks, based on three customers chosen at random in each week. The data consist of the response time (in minutes) for three customers each over 32 weeks. The data are shown below and included on the course Blackboard site. Use control chart(s) to determine if the process is stable. Eliminate all subgroups that constitute Shewhart rule violations assuming that a root cause is found and eliminated.

Week	Response Time (Min.)
1	450	522	522
2	300	570	426
3	534	486	540
4	462	606	354
5	474	582	354
6	444	462	528
7	426	282	600
8	438	456	528
9	492	576	558
10	402	546	504
11	510	426	336
12	510	342	444
13	402	474	546
14	366	438	444
15	510	510	522
16	492	510	504
17	480	576	420
18	630	474	462
19	546	342	408
20	612	600	570
21	564	558	486
22	486	588	432
23	468	390	492
24	366	462	372
25	498	534	582
26	420	408	426
27	432	558	510
28	504	630	456
29	462	396	510
30	336	426	528
31	480	402	462
32	498	480	324