Exam 25: Process Capability and Spc

You are developing an "X-bar" chart based on sample means.You know the standard deviation of the sample means is 4,the desired confidence level is 99 percent and the average of the sample means is 20.Which of the following is your LCL?

In variables sampling the actual measurements of the variable observed are used regardless of whether the unit is good or bad.

If the fraction defective is 0.12 based on a sample size of 16,what is the standard deviation to be used when constructing a "p" chart?

With which of the following should we use an "X-bar" chart based on sample means to monitor process quality?

A quality control chart has upper and lower control limits expressed as lines on a chart.As long as the sample values fall between these two lines there is no need to investigate process behavior.

If there are 400 total defects from 8 samples,each sample consisting of 20 individual items in a production process,which of the following is the fraction defective that can be used in a "p" chart for quality control purposes?

You want to determine the control lines for a "p" chart for quality control purposes.If the total number of defects from all samples is 2,000,the number of samples is 100 and the sample size is 50,what would be the standard deviation used in developing the control lines?

If the fraction defective is 0.4 based on a sample size of 100,the standard deviation used in the "p" chart is about 0.10.

Variation that is inherent in a production process itself is called assignable variation.

In acceptance sampling,the number of units in the sample (n)is determined by the interaction of the acceptable quality level (AQL),the lot tolerance percent defective (LTPD),the probability of rejecting a high quality lot (alpha)and the probability of accepting a low quality lot (beta).

For which of the following should we use a "p" chart to monitor process quality?

You have just used the capability index (C_pk)formulas to compute the two values "min [1,1]".Which of the following is the proper interpretation of these numbers?

You have 75 total defects from 100 different samples of 15.What is p?

You want to determine the control lines for a "p" chart for quality control purposes.If the total number of defects from all samples is 560,the number of samples is 70 and the sample size is 80,which of the following would be the standard deviation used in developing the control lines?

You want to develop a three-sigma "R" chart.You know the average range is 12 based on several samples of size 6.Which of the following is the resulting LCL?

Statistical process control involves testing random samples of output from a process to determine whether the process is producing items within a pre-selected range.

The capability index (C_pk)indicates the position of the mean and tails of a processes variance relative to design specifications

If you are going to develop an "R" chart based on range statistics and you are using a sample size of 9 for your charting purposes.Which of the following is the lower control limit D3 factor for the chart?

You are developing an "X-bar" chart based on sample means.You know the standard deviation of the sample means is 4,the desired confidence level is 99.7 percent and the average of the sample means is 24.What is your UCL?

If there are 120 total defects from 10 samples,each sample consisting of 10 individual items in a production process,which of the following is the fraction defective that can be used in a "p" chart for quality control purposes?