Exam 14: Statistical Methods for Quality Control

Control charts that are based on data indicating the presence of a defect or the number of defects are called ______ control charts.

If the value of c in a single-stage sampling plan is increased, with n remaining constant, the probability of accepting the lot

Producer's risk is

An acceptance sampling plan uses a sample of 18 with an acceptance criterion of zero. Determine the probability of accepting shipments that contain 5, 10, 15, 20, 25, 30, 35, 40, and 45% defective units.

The quality control department of a company has decided to select a sample of 10 items from the shipments received; and if the sample contains no defective parts, the entire shipment will be accepted. a.If there are 40 defective items in a shipment, what is the probability that the entire lot will be accepted? b.Use the binomial table and read the probability of accepting lots that contain 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50% defective units.

Which of the following is not a type of a control chart?

Ledd Electronics has received a large shipment of power supply units for the desktop computers being assembled. The units are coming from a new supplier and Ledd is not sure what the actual defect rate will be for this component. Ledd is considering an acceptance sampling plan with n = 30 and c = 1. a. Find the probability of accepting a lot when the defect rate is 2%, 4%, and 6%. b. What happens to the producer's risk as the defect rate increases? c. What happens to the consumer's risk as the defect rate increases?

Process control and acceptance sampling procedures are most closely related to

If the value of c in a single-stage acceptance sampling plan is increased, with n remaining constant, the probability of accepting the lot

In acceptance sampling, the risk of rejecting a good quality lot is known as

A statistical procedure in which the number of defective items found in a sample is used to determine whether a lot should be accepted or rejected is called

The maximum number of defective items that can be found in the sample and still lead to acceptance of the lot is

A production process is considered in control if 6% of the items produced are defective. Samples of size 300 are used for the inspection process. a.Determine the standard error of the proportion. b.Determine the upper and the lower control limits for the p chart.

The three quality processes on which Juran's approach to quality focused include all of the following except

In acceptance sampling, the risk of accepting a poor quality lot is known as

The entire system of policies, procedures, and guidelines established by an organization to achieve and maintain quality is called

Accepting a good-quality lot would be a

The control limits for an np chart are how many standard deviations above and below the expected number of defectives?

A production process that is in control has a mean () of 80 and a standard deviation () of 10. a.Determine the upper and the lower control limits for sample sizes of 25. b.Five samples had means of 81, 84, 75, 83, and 79. Construct an x-bar chart and explain whether or not the process is in control.

A soft drink filling machine is set up to fill bottles with 12 ounces of soft drink. The standard deviation s is known to be 0.4 ounces. The quality control department periodically selects samples of 16 bottles and measures their contents. Assume the distribution of filling volumes is normal. a.Determine the upper and lower control limits and explain what they indicate. b.The means of six samples were 11.8, 12.2, 11.9, 11.9, 12.1, and 11.8 ounces. Construct an x-bar chart and indicate whether or not the process is in control.