Telephone inquiries of 100 IRS “customers” are monitored daily at random by Xiangling Hu. Incidents of incorrect information or other nonconformities (such as impoliteness to customers) are recorded. The data for last week follow:

DAY 1 2 3 4 5 NO. OF NONCONFORMITIES 5 10 23 20 15

a) Construct a 3-standard deviation c-chart of nonconformities.

b) What does the control chart tell you about the IRS telephone operators? L 0 1