A manufacturer produces micron chips for personal computers. From past experience the production manager believes that 1 % of the chips are defective. The company collected a sample of the first 1,000 chips manufactured after 4:00 P.M. every other day for a month. The chips were analyzed for defects, then these data and MINITAB were used to construct the p-chart shown on page 691.
a. From a statistical perspective, is a sample size of 1,000 adequate for constructing the p-chart'! Explain
b. Calculate the chart's upper and lower control limits
c. What does the p-chart suggest about the presence of special causes during the time when the data were collected?
d. Critique the rational subgrouping strategy used by the disk manufacturer.
