Question: Regis Printing Company performs printing services for individuals and business customers. Many of the jobs require that brochures be folded for mailing. The company has a machine that does the folding. It generally does a good job, but it can have problems that cause it to do improper folds. To monitor this process, the company selects a sample of 50 brochures from every order and counts the number of incorrectly folded items in each sample. Until now, nothing has been done with the 300 samples that have been collected. The data are located in the file Regis.
a. What is the appropriate control chart to use to monitor this process?
b. Using the data in this file, construct the appropriate control chart and label it properly.
c. Suppose that for the next three orders, sample sizes of 50 brochures are examined with the following results:
Sample Number 301 302 303
Number of Bad Folds 6 9 7
Plot the appropriate data to the control chart and indicate whether any of the control chart signals are present. Discuss your results.
d. Suppose that the next sample of 50 has 14 improperly folded brochures. What conclusion should be reached based on the control chart? Discuss.