1. A professor records the number of complaints from his students each semester throughout a 15-semester period. The sample size for each sample is 50 students, what are 3-sigma control limits for this class? Construct a control chart and interpret the data.

Semester number	Complaints
1	8
2	9
3	8
4	6
5	6
6	20
7	10
8	10
9	4
10	3
11	8
12	10
13	7
14	4
15	2