Exam 19: Statistical Process Control and Quality Management

A new machine used in the production of motor mount bolts was put into operation. Five samples of size 100 were randomly selected and the number of defectives in each sample was noted. What is the average percent defective?

A quality control chart is used to monitor the customer wait time at a local call center. Sample means of five times are averaged and plotted over time. Over the last hundred sample means, one sample mean was outside a control limit. The process is

What type of variation can be reduced, or even eliminated and is usually nonrandom in nature?

The purpose of a statistical quality control chart is to identify when assignable causes of variation have entered the production system so that the cause may be identified and corrected.

If the binomial distribution is used to develop an operating characteristic curve for an acceptance sampling plan, then the trials must be ________________.

One purpose of quality control is to reduce the costs associated with producing and delivering poor quality goods and services.

A new printing machine is set or calibrated to print 25 copies per minute. On each of four days, the printer's output is measured five times. The data will be used to construct a process control chart to monitor the printing process. The results of the printing process are in the following table. What is the value of A₂, the control limit factor for averages?

A chart used to show the results of a Pareto analysis is a

The technique that tallies types of defects and their frequency is called

A major distributor buys shoes from a supplier. The distributor randomly samples the shoes to inspect for quality. The distributor's specifications state that a delivery of 100 pairs of shoes will be accepted only if the number of defective pairs of shoes in a sample of 10 pairs is two or less. Based on the sampling plan, what is the probability of accepting the delivery of 100 pairs of shoes if the actual percent defective is 0.50?

A new printing machine is set or calibrated to print 25 copies per minute. On each of four days, the printer's output is measured five times. The data will be used to construct a process control chart to monitor the printing process. The results of the printing process are in the following table. What is the value for the lower control limit (LCL) of the range chart?

In acceptance sampling, usually 100% of the incoming lot is checked.

What causes of variation cannot be entirely eliminated? _____________

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the value of the upper control factor of the range?

What is the purpose of quality control in production and service operations?

A quality control chart is used to monitor the customer wait time at a local call center. Sample means of five times are averaged and plotted over time. The last fifty sample means are randomly distributed between the upper and lower control limits. The process is

The Quality Assurance Department selected a sample of 12 printed circuit boards and tested them. The number of defects in each circuit board was 3, 3, 0, 5, 1, 1, 5, 6, 6, 2, 0, and 1. What kind of control chart should be constructed to monitor the process?

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the range of the samples at 7 am?

Which probability distribution is used to develop a control chart for sample means?

Random samples of 4 items are selected from a manufacturing process at regular intervals and a certain quality characteristic is measured. After 25 samples, $\Sigma$ X = 15,350 and $\Sigma$ R = 411.4 What is the sample size?