Five data entry operators work at the data processing department of the Royal 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:

a) Establish 3s 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 limits are 0.10 and 0.01, respectively. What does this imply about Royal Banks own standards?

Sample No. Sample No. Sample No. No. Defective No. Defective No. Defective 11 17 12 12 18 5 16 4 21 22 23 7 5 19 13 6 NOUL AWN- 14 24 10 7 13 11 25 8 10 15 16 17 18 19 26 27 11 8 12 12 28 9 4 6 16 WNO 12 29 6 10 20 30 13