please help

Five data entry operators work at the data process- D-stpartment 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 SAMPLENO NO DEFECTIVENO.DEFECTIVENODEFECTIVE 18 21 17 12 12 23 24 25 26 27 28 29 30 19 13 16 10 13 10 14 15 16 17 18 19 20 12 12 9 12 10 13 16 a) Establish 3 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