Question

MULTIPLE CHOICE

PLEASE MAKE SURE OF ANSWER

8. Control Charts for Slow Processes

1 point possible (graded)

The usage of which of the following charts is suggested for slow moving processes according to the lecture?

A- R chart

B- X chart

C- X-bar chart

9. MA and MR Charts 1

1 point possible (graded)

Which of the following statements about moving average (MA) and moving range (MR) charts is NOT correct?

A- Moving average (MA) and MR charts use sample averages and sample ranges, as do the regular X- and R-charts, but the method of forming the samples or subgroups is different.

B- The averaging done in the MA and MR charts reduces the noise and helps in discovering the signals.

C- The averaging done in the MA and MR charts always increases noise – independent of the sample size – and makes discovering the signals more difficult.

10. MA and MR Charts 2

1 point possible (graded)

Which of the following statements about the impact of the size of subgroups for moving average (MA) and moving range (MR) charts is correct?

A- Larger subgroups smooth variations and thus help to detect changes.

B- Smaller subgroups are more responsive and less sensitive to noise.

C- Larger subgroups smooth variations but may hide changes.

11. EWMA-Chart

1 point possible (graded)

Which of the following statements about the EWMA-Chart is correct?

A- The EWMA charts is a chart whose sensitivity or power can be changed by changing the value of lambda.

B- EWMA is an abbreviation for Estimated Weighted Moving Average.

C- The EWMA charts is a chart whose sensitivity or power cannot be changed.

12. S-Chart

1 point possible (graded)

Which of the following statements about the S-Chart is NOT correct?

A- An S-chart (standard deviation chart) is used instead of R-chart when the sample size has to be small, because the R-chart loses in efficiency when the sample size becomes small, n smaller 10.

B- An S-chart (standard deviation chart) is used instead of R-chart when the sample size has to be large, because the R-chart loses in efficiency when the sample size becomes large, n larger 10.

C- Sometimes we need large sample size due to dictated circumstances, such as when extra sensitivity through a larger sample size is desired. Then, the S-chart should be used in place of the R-chart to accompany the X-bar chart.

Answer 1

8. D- MA and MR charts

These charts are used when the process is too slow to produce sufficient data for grouping to be feasible.

9. C- The averaging done in the MA and MR charts always increases noise – independent of the sample size – and makes discovering the signals more difficult.

10. B- Smaller subgroups are more responsive and less sensitive to noise.

11. A- The EWMA charts is a chart whose sensitivity or power can be changed by changing the value of lambda.

12. A- An S-chart (standard deviation chart) is used instead of R-chart when the sample size has to be small, because the R-chart loses in efficiency when the sample size becomes small, n smaller 10.