Exam 15: Statistical Quality Control

A coffee company is attempting to make certain that all its packaged coffee beans contain the same amount of coffee bean by weight.Over the last few days, it has taken several samples.The overall average weight of the sampled packages is 16 ounces, with an average range of 4 ounces.Each sample was of five packages.What would be the 99.7 upper and lower control limits for an -chart?

Defects in marble countertops usually require the whole top to be reconstructed.In one kitchen shop, the percent defective in the past has been one percent.If a sample size of 30 is taken, what should the 95.5 percent upper control limit be?

A professor gives a series of twenty quizzes in his operations planning and control class just to keep his students on their toes.Each quiz consists of fifty questions and the results for one student (the number of questions missed on each exam)are shown in the table.Construct an appropriate control chart for this situation.Is the student in control?

A company has been receiving complaints about the attitude of some sales clerks.Over a 10-day period, the total number of complaints was 250.The company wishes to develop a control chart for the number of complaints.What would the lower control limit on the number of complaints per day be for a 3 sigma (99.7%)control chart?

A c-chart is based on which of the following probability distributions?

Which of the following is not a popular definition of quality?

For data that are appropriately handled by C-charts, the mean equals the variance.

It is impossible to develop a process that has zero variability.

Explain the difference between control charts for variables and attributes.

When receiving a shipment from a supplier, inspection must be done to check the fraction of defective products.This is best monitored by which of the following control charts?

Which of these patterns on a control chart would require a worker to stop the process and investigate for an assignable cause?

Table 15-1 -Refer to Table 15-1.The average range of a process for packaging cereal is 1.1 ounces.If the sample size is 10, find the upper control chart limit for the range chart.

Technically, to achieve Six Sigma quality, there would have to be fewer than 3.4 defects per million opportunities.

The underlying distribution for a p-chart is binomial.

Joe studied his control chart and noticed it had been built with repeated samples of ten units and three sigma limits that were UCL = 109.0125 and LCL = 90.9875.What is the process standard deviation?

C-charts are used to analyze the proportion defective in a sample.

TQM emphasizes quality of the goods or service-producing division of the company.

If all of the control points on a control chart lie between the UCL and the LCL, the process is always in control.

A quality control program is being developed for batteries.The percent defective for these in the past has been 3%.If a sample size of 120 is taken, what would the 99.7% upper control chart limit be?

A company has been receiving complaints about the attitude of some sales clerks.Over a 10-day period, the total number of complaints was 360.The company wishes to develop a control chart for the number of complaints.What would the upper control limit on the number of complaints per day be for a 3 sigma (99.7%)control chart?