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 250 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 17 2 5 12 4 22 12 3 19 13 16 23 7 4 9 14 3 24 6 5 10 15 10 25 14 6 9 16 9 26 11 7 12 17 13 27 14 8 10 18 5 28 6 9 5 19 18 29 11 10 13 20 16 30 2 a) establish 3sigma upper and lower control limits.