Data were collected from a process in which the factor of
interest was whether the finished item contained a particular attribute. The
fraction of items that did not contain the attribute was recorded. A total of
30 samples were selected. The common sample size was 100 items. The total
number of nonconforming items was 270. Based on these data, compute the upper
and lower control limits for the p-chart.
Explain why it is important to update the control charts as
soon as new data become available.
The Haines Lumber Company makes plywood for residential and
commercial construction. One of the key quality measures is plywood thickness.
Every hour, five pieces of plywood are selected and the thicknesses are
measured. The data (in inches) for the first 20 subgroups are in the file