The local newspaper receives several complaints per day about typographic errors. Over a seven-day period, the publisher has received calls from readers reporting the following total daily number of errors: 4, 3, 2, 6, 7, 3, and 9. Based on these data alone, what type of control chart(s) should the publisher use?

Statistical process control (SPC) is a data-driven process that uses statistical methods to monitor and control the quality of a production process. The goal of SPC is to ensure that the process is stable, consistent with customer requirements, and not drifting or changing in an unexplainable manner. 

SPC is commonly used in manufacturing or production processes to measure how consistently a product performs according to its design specifications. Some of th