An electronics company manufactures several types of cathode-ray tubes on a mass production basis. To monitor the process, 50 tubes of a certain type were randomly sampled from the production line and inspected each day over a 1-month period. The number of defectives found each day is provided in the accompanying table.

a. Construct a p-chart for the sample fraction of defective cathode-ray tubes.

b. Locate the center line on the p-chart.

c. Locate the upper and lower control limits on the p-chart.

d. Does the process appear to be in control? If not, modify the control limits for future data.

e. Conduct a runs analysis to detect a trend in the production process.

Transcribed Image Text:

CRTUBE Day Number Defective Day Number Defective 1 11 12 23 15 13 15 12 14 12 4 10 15 11 9 16 11 12 17 16 7 12 18 15 8 14 19 10 9 9 20 13 10 13 21 12 11 15 2. 3.