Exam 14: Statistical Methods for Quality Control

The sample result plotted on an np control chart is

A control chart used when the output of a process is measured in terms of the mean value of a variable such as a length, weight, temperature, and so on is

Normal or natural variation in the quality of production output that is due purely to chance is called

Juran proposed a simple definition of quality:

We can examine the effect of the sampling plan on both types of risks by varying the assumed

The No-Cal Bottling Company bottles soft drinks for sale to government commissaries. The bottles come in only one flavor (chocolate-lemon) and only one size (32 ounces). Joan Stickler, the quality control officer for the commissaries, wants to keep track of the fill weights of No-Cal and begins to draw daily samples of 100 bottles from the daily receipts. The first ten sample means and ranges are: If sample ranges ordinarily average 2.5 ounces: a. Compute 3s control limits for sample means. b. Compute 3s control limits for sample ranges. c. What would you conclude about the fill weights of NoCal?

The following data represent the filling weights based on samples of 350-gram containers. Ten samples of size 5 were taken. Use Excel to develop an x-bar chart.

A process that is in control has a mean of  = 56.5 and a standard deviation of  = 3.4. What should the control limits be for a sample mean chart if samples of size 8 are taken?

The control limits for an x-bar chart are how many standard deviations above and below the process mean?

A form of acceptance sampling in which more than one sample or stage is used is called a

A production process is considered in control if 4% of the items produced are defective. Samples of size 100 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 weight of bags of cement filled by Granite Rock Company's packaging process is normally distributed with a mean of 50 pounds and a standard deviation of 1.5 pounds when the process is in control. What should the control limits be for a sample mean, , chart if 9 bags are sampled at a time?

The control limits for a p chart are how many standard deviations above and below the proportion defective?

A control chart that is used when the output of a production process is measured in terms of the proportion defective is

A process sampled 30 times with a sample of size nine resulted in = 12.7 and = 0.8. Compute the upper and lower control limits for the and charts for this process.

An acceptance sampling plan with n = 20 and c = 1 has been designed with a producer's risk of .12. a. Was the value of p₀ equal to .02, .03, .04, or .05? b. What is the consumer's risk associated with this plan if p₁ is .08? c. Assume the consumer's risk found in (b) is unacceptably high. Which modification of the sampling plan will result in the greater reduction of the consumer's risk, increasing n to 30 or decreasing c to 0?

A control chart that is used to monitor the number of defectives in a sample is

Which of the following is a statistical method used in quality control?

In contrast to Deming's philosophy, which required a major cultural change in the organization, Juran's programs were designed to improve quality by

The second stage of a two-stage acceptance sampling plan is executed when the first-stage result is