Telephone inquiries of 100 IRS “customers” are monitored daily at random. Incidents of incorrect information or other non-conformities (such as impoliteness to customers) are recorded. The data for last week follow:
Day No. of Nonconformities
1............... 5
2............... 10
3............... 23
4............... 20
5............... 15
(a) Construct a 3-standard deviation c-chart of nonconformities.
(b) What does the control chart tell you about the IRS telephone operators?