7. You are the newly appointed assistant administrator at a local hospital, and your first project is to investigate the quality of the patient meals put out by the food-service department. You conducted a 10 day survey by submitting a simple questionnaire to the 400 patients with each meal, asking that they simply check off that the meal was either satisfactory or unsatisfactory. For simplicity in this problem, assume that the response was 1,000 returned questionnaires from the 1,200 meals each day. The results are as follows:
Number of Unsatisfactory Meals Sample Size
December 1 74 1000
December 2 42 1000
December 3 64 1000
December 4 80 1000
December 5 40 1000
December 6 50 1000
December 7 65 1000
December 8 70 1000
December 9 40 1000
December 10 75 1000
a. Formulate and construct the statistical process control using a confidence interval of 95.5 percent (which is two standard deviations)
b. What comment can you make about the results of the survey?
8. Pool Technology uses microprocessor from a supplier in Asia. This microprocessor is used in the assembly process of the remote control unit to adjust the pool and spa temperature. The yield of this manufacturing process is not high, so the AQL specified by manufacturer is 0.15 while the LTPD is at 0.40. Microprocessors arrive in large containers and require 1 inspector to do incoming inspection.
a. Develop a sampling plan.
b. Explain what the sampling plan means, that is, how would you tell the inspector to do the incoming test.
c. Inspector inspected one of the container and found 5 units out of the determined sample size to be defective. Should the inspector reject or accept this container of microprocessors.