A computer manufacturer has decided to initiate a control chart program to monitor the quality performance of their wire wrapping operation on their circuit boards. The boards are randomly tested and those that fail are sent back for rework. 40 boards are tested per day. Control limits were set at two standard deviations with target rework of 2% when the process is operation correctly. The percent of boards that required rework from 10 random samples were 3.1, 2.2, 3.0, 0.0, 2.0, 2.4, 2.1, 1.0, 1.6, 2.6.
a. What is the center line for the p chart?
b. What are the upper and lower control limits respectively for the p chart?
c. What is happening to the process?