The number of imperfections in bond paper produced by a paper mill is observed over a period of…

The number of imperfections in bond paper produced by a paper mill is observed over a period of several days. Table 8-28 shows the area inspected and the number of imperfections for 25 samples. Construct a control chart for the number of imperfections per square meter. Revise the limits, if necessary, assuming special causes for the out-of-control points.