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. SAMPLE NO. NO. DEFECTIVE 18 NO. DEFECTIVE 7 5 SAMPLE NO. 21 22 1 NO. DEFECTIVE 17 12 11 2 12 5 3 19 13 16 23 6 4 10 14 4 24 7 5 11 15 11 25 13 6 8 16 8 26 10 7 17 12 27 14 12 9 8 18 4 28 6 9 6 19 6 29 12 10 13 20 16 30 3 a) Establish 3o upper and lower control limits. b) Why can the lower control limit not be a negative number? c) The industry standards for the upper and lower control lim- its are 0.10 and 0.01, respectively. What does this imply about Birmingham Bank's own standards? PX