MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Statistical Quality Control knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The points plotting below the lower control limit of p-chart do not always represent the out-of-control process or an assignable cause. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2. |
Even if 100% inspection is done, control chart can have a variable sample size. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3. |
The approximate upper control limit calculated for control chart limits based on an average sample size, is expressed by _____ |
| A. | UCL=\(\bar{p} + 0.5\sqrt{\bar{p}(1-\bar{p})/\bar{n}}\) |
| B. | UCL=\(\bar{p} + \sqrt{\bar{p}(1-\bar{p})/\bar{n}}\) |
| C. | UCL=\(\bar{p} – 3\sqrt{\bar{p}(1-\bar{p})/\bar{n}}\) |
| D. | UCL=\(\bar{p} + 3\sqrt{\bar{p}(1-\bar{p})/\bar{n}}\) |
| Answer» E. | |
| 4. |
In the case of average sample size based control limits, which of these states the correct expression for average sample size? |
| A. | \(\bar{n}=\frac{∑_{i=0}^m n_i}{m}\) |
| B. | \(\bar{n}=\frac{∑_{i=1}^m n_i}{m}\) |
| C. | \(\bar{n}=\frac{∑_{i=1}^m n_i}{m-1}\) |
| D. | \(\bar{n}=\frac{∑_{i=1}^m n_i}{1-m}\) |
| Answer» C. \(\bar{n}=\frac{∑_{i=1}^m n_i}{m-1}\) | |
| 5. |
Which one of these is not a method to plot the variable sample size data on p-chart? |
| A. | Variable-width control limits |
| B. | Control limits based on average sample size |
| C. | Tolerance diagram |
| D. | Standardized Control Chart |
| Answer» D. Standardized Control Chart | |
| 6. |
For a process, there are 25 samples taken from its output of variable sample size. There are total 234 defects in all the samples combined. If the total of all the sample sizes is 2450, what will be the value of the UCL in the case of variable-width control limits of p-chart? |
| A. | \(0.096+3\sqrt{0.096*\frac{0.904}{n_i}}\) |
| B. | \(0.087+3\sqrt{0.087*\frac{0.913}{n_i}}\) |
| C. | \(0.096-3\sqrt{0.096*\frac{0.904}{n_i}}\) |
| D. | \(0.087-3\sqrt{0.087*\frac{0.913}{n_i}}\) |
| Answer» B. \(0.087+3\sqrt{0.087*\frac{0.913}{n_i}}\) | |
| 7. |
What is the expression to calculate the variable-width control limits for the p-chart? |
| A. | \(\bar{p} \pm \frac{1}{2} \sqrt{\bar{p}(1-\bar{p})/n_i}\) |
| B. | \(\bar{p} \pm \sqrt{\bar{p}(1-\bar{p})/n_i}\) |
| C. | \(\bar{p} \pm 3\sqrt{\bar{p}(1-\bar{p})/n_i}\) |
| D. | \(\bar{p} \pm \sqrt{\bar{p}(1-\bar{p})/n_i}\) |
| Answer» D. \(\bar{p} \pm \sqrt{\bar{p}(1-\bar{p})/n_i}\) | |
| 8. |
For a control chart data having the average sample fraction nonconforming= 0.2313 and the sample size=50, what will be the value of the UCL for the np control chart? |
| A. | 2.62 |
| B. | 20.510 |
| C. | 11.56 |
| D. | 11.892 |
| Answer» C. 11.56 | |
| 9. |
If the p=0.2313 for a np chart, and the number of items in a sample are 50, what will be the center line value of the np chart? |
| A. | 10.34 |
| B. | 11.56 |
| C. | 10.11 |
| D. | 13.21 |
| Answer» C. 10.11 | |
| 10. |
The center line of the np-control chart represents the value equal to ____________ |
| A. | p |
| B. | p |
| C. | np |
| D. | 1-np |
| Answer» D. 1-np | |
| 11. |
The number nonconforming chart is also called ___________ |
| A. | np-chart |
| B. | p-chart |
| C. | c-chart |
| D. | s-chart |
| Answer» B. p-chart | |
| 12. |
If the probability of a unit being conforming or nonconforming, depends on the previous unit being conforming or nonconforming, can p-chart be applied on the process? |
| A. | Yes |
| B. | No |
| C. | This depends on the sample size |
| D. | This depends on the operator changes |
| Answer» C. This depends on the sample size | |
| 13. |
For narrower limits of control, which of this is true? |
| A. | Chart becomes insensitive to small shift |
| B. | Chart becomes more sensitive to small shift but gives false alarms |
| C. | Chart becomes more sensitive to small shift but gives accurate alarms |
| D. | Chart gives no alarms at all |
| Answer» C. Chart becomes more sensitive to small shift but gives accurate alarms | |
| 14. |
For what value of sample size, will the p-chart will have a LCL value higher than 0 when p=0.05 and 3 sigma limits are used? |
| A. | n>121 |
| B. | n>100 |
| C. | n>125 |
| D. | n>171 |
| Answer» E. | |
| 15. |
For LCL for the p-chart to be higher than zero, what condition should the sample size fulfill? |
| A. | \(n>\left[\frac{(1-p) L^2}{p}\right] \) |
| B. | \(n>\left[\frac{(1-p) L^2}{2p}\right] \) |
| C. | \(n<\left[\frac{(1-p) L^2}{2p}\right] \) |
| D. | \(n<\left[\frac{(1-p) L^2}{p}\right] \) |
| Answer» B. \(n>\left[\frac{(1-p) L^2}{2p}\right] \) | |