Five data entry operators work at the data processing department of the Birmingham Bank. Each day for 30 days, the number of defective records in a sample of 350 records typed by these operators has been noted, as follows:

Sample No.	No. Defectives	Sample No.	No. Defectives	Sample No.	No. Defectives
1	7	11	7	21	18
2	4	12	6	22	11
3	18	13	17	23	6
4	9	14	3	24	8
5	11	15	10	25	14
6	8	16	8	26	10
7	13	17	13	27	14
8	9	18	3	28	5
9	6	19	18	29	13
10	12	20	17	30	3

a) Establish 3 upper and lower control limits. UCLp =

b) Establish 3o upper and lower ocntrol limits LCLp=