A Bank Officer Wishes to Study How Many Customers Write

A bank officer wishes to study how many customers write bad checks.To accomplish this,the officer randomly selects a weekly sample of 100 of checking accounts,and the number of who wrote bad checks was recorded.The numbers of customers who wrote bad checks in 20 consecutive weekly samples of 100 cardholders are,respectively, 1,4,9,0,4,6,0,3,8,5,3,5,2,9,4,4,3,6,4,0
On the basis of the limits established,if the bank finds that 12 customers in next week's sample of 100 cardholders have written bad checks,should the bank believe that there has been an unusual variation in the process?

A) Yes
B) No