Exam 20: Statistical Methods for Quality Control

The upper and lower control limits of the proportions of defectives of a process are 0.0803 and 0.0161 a.What has been the proportion of defectives in this process? b.What has been the sample size? c.Determine the standard error of proportion.

The upper and lower control limits of the proportions of defectives of a process are 0.13 and 0.07. a.What has been the proportion of defectives in this process? b.What has been the sample size?

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.

A group of items such as incoming shipments of raw material is called a(n)

Nancy,Inc.manufactures 4 ounce chocolate bars.Random samples of size four were taken and weighed.Eight hours of observation provided the following data. a.Determine the 3 sigma upper and lower control limits for the x-bar chart. b.Determine the 3 sigma upper and lower control limits for the R-chart.

A production process that is in control has a mean ( $\mu$ )of 80 and a standard deviation ( $\sigma$ )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 production process is set up to fill containers with 16 ounces of liquid.The standard deviation $\sigma$ is known to be 0.5 ounces.The quality control department periodically selects samples of 25 containers and measures the contents.(Assume the distribution of filling volumes is normal. ) a. a.Determine the upper and lower control limits. b.Explain the meaning of the values you found in part

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

Variations in process output that are due to factors such as machine tools wearing out are

Consumer's risk is