1.
Attributes (i.e. attribute data) must be measured rather than counted
Correct Answer
B. False
Explanation
This statement is false. Attributes can be both measured and counted, depending on the nature of the attribute. Some attributes, such as height or weight, can be measured using numerical values. On the other hand, attributes like hair color or eye color can be counted using categories or labels. Therefore, it is not necessary for attributes to be measured rather than counted.
2.
What type of error occurs when it is concluded that a process is not in control (i.e. not stable) when actually it is
Correct Answer
A. Type i error
Explanation
A type I error occurs when it is concluded that a process is not in control (i.e. not stable) when actually it is. This means that the conclusion is incorrect and the process is actually in control. Type I errors are also known as false positives, where a hypothesis is rejected even though it is true. In this case, the error arises from incorrectly concluding that the process is not stable, leading to potential unnecessary actions or interventions.
3.
If a sample result on a control chart falls outside one of the control limits, this suggests that the process output is non random (i.e. not in control) and should be investigated
Correct Answer
A. True
Explanation
If a sample result on a control chart falls outside one of the control limits, it indicates that the process output is not random and is not in control. This means that there is a potential issue or variation in the process that should be investigated. Control limits are set based on the expected variation of the process, and any data points outside these limits suggest that the process is not operating as expected. Therefore, it is important to investigate and address the cause of the non-random variation to ensure the process is functioning properly.
4.
The two types of variation that a process could display are:
Correct Answer
A. Assign variation and random variation
Explanation
The correct answer is "assigned variation and random variation." This is because a process can have variation that is assigned or intentional, such as when changes are made to the process to improve performance or address specific issues. On the other hand, a process can also have random variation, which is unpredictable and occurs naturally. These two types of variation can affect the outcome of a process and need to be understood and managed to ensure consistent results.
5.
Which of the following is not an inspection point in manufacturing
Correct Answer
E. All of the above are inspection points
Explanation
The correct answer is that all of the options listed are inspection points in manufacturing. This means that raw materials and purchased parts, finished products, before a costly operation, and before a covering process are all areas where inspections are typically conducted to ensure quality and identify any potential issues or defects.
6.
For which of the following would a range (r) chart be used?
Correct Answer
B. Monitor process dispersion (i.e. width)
Explanation
A range (r) chart would be used to monitor process dispersion or width. This chart is used to measure the variation or spread of data within a process. By plotting the range of values between consecutive data points, it helps to identify if the process is stable or if there are any significant changes in the dispersion. This chart is particularly useful in identifying shifts or trends in variability, which can help in identifying potential quality issues and taking corrective actions.
7.
The purpose of control charts is to
Correct Answer
D. Distinguish between random variation and assignable variation in the process
Explanation
Control charts are used to distinguish between random variation and assignable variation in a process. Random variation refers to natural fluctuations in the output, while assignable variation refers to specific causes that can be identified and addressed. By analyzing the data plotted on a control chart, any patterns or trends can be identified, indicating whether the process is performing within acceptable limits or if there are any assignable causes that need to be addressed. Therefore, the purpose of control charts is to distinguish between these two types of variations.
8.
A change in the process mean (i.e., process average) for a measured characteristic (i.e. variable data) would most likely be detected by a:
Correct Answer
B. X bar chart
Explanation
An x bar chart is used to monitor the process mean or average of a measured characteristic in variable data. It plots the sample means over time and calculates control limits to determine if the process mean is within acceptable limits. If there is a change in the process mean, it is likely to be detected by the x bar chart as it will show a shift or trend in the sample means. The other charts mentioned (p chart, c chart, and r chart) are used for monitoring different aspects of the process and may not be as effective in detecting changes in the process mean.
9.
Qualitative control
Correct Answer
B. A process that evaluates output relative to a standard and takes corrective action when output doesn't meet standards
Explanation
Qualitative control refers to the process of evaluating the output of goods or services in relation to a set standard. It involves assessing the quality of the output and comparing it to the predetermined criteria. If the output does not meet the established standards, corrective action is taken to rectify the issue and bring the output back to the desired level of quality. This ensures that the goods or services meet the required standards and satisfy customer expectations.
10.
Inspection
Correct Answer
A. Appraisal of goods or services
Explanation
The term "inspection" refers to the act of evaluating or assessing the quality or condition of goods or services. It involves closely examining the products or services to ensure that they meet certain standards or requirements. This can include checking for defects, verifying specifications, and comparing the output to a predetermined standard. If any discrepancies or deviations are found, corrective action is taken to address the issues and bring the output back to the desired standard. Therefore, the answer "appraisal of goods or services" accurately describes the process of inspection.
11.
Inspection issues:1. how much to inspect and how often2. at what points in the process inspection should occur3. whether to inspect in a centralized or on site location4. whether to inspect attributes (i.e. count the number of times something occurs) or variables (i.e. measure the value of a characteristic)
Correct Answer
A. True
Explanation
The given answer is true. The question is discussing various issues related to inspection, such as how much to inspect and how often, where in the process inspection should occur, whether to inspect in a centralized or on-site location, and whether to inspect attributes or variables. The answer indicates that these issues are indeed inspection issues, implying that they are valid points to consider when conducting inspections.
12.
Quality of conformance
Correct Answer
A. A product or service conforms to specifications
Explanation
The term "quality of conformance" refers to the degree to which a product or service meets the specified requirements or specifications. It indicates that the product or service has been produced or delivered in accordance with the established standards and criteria. In other words, it signifies that there is a match between what was intended or expected and what was actually delivered. This term is often used in quality management to assess the level of compliance and to ensure that the desired level of quality is achieved.
13.
Statistical process control (spc)
Correct Answer
B. Statistical evaluation of the output of a process
Explanation
The correct answer is "statistical evaluation of the output of a process." This means that statistical process control (SPC) involves analyzing the data and results of a process to determine if it is operating within acceptable limits and meeting the required specifications. SPC helps identify any variations or deviations in the output of a process, which can be caused by numerous minor factors. By evaluating the statistical data, organizations can make informed decisions and take corrective actions to improve the process and ensure that the product or service meets the desired standards.
14.
Random variation
Correct Answer
A. Natural variation in the output of a process, created by countless minor factors
Explanation
The correct answer is "natural variation in the output of a process, created by countless minor factors." This explanation suggests that random variation refers to the inherent variability in the output of a process, which is caused by numerous minor factors. These factors can include small fluctuations in input variables, environmental conditions, or human error. Random variation is a normal occurrence and cannot be completely eliminated, but it can be managed and controlled through statistical evaluation and process improvement techniques.
15.
Assignable variation is in process output, a variation whose cause can be identified. a nonrandom variation
Correct Answer
A. True
Explanation
The given statement is true. Assignable variation refers to a type of variation in process output where the cause can be identified. It is also known as nonrandom variation. This means that the variation is not due to chance or random factors, but rather has a specific cause that can be identified and addressed.
16.
Sampling distribution is a theoretical distribution of sample statistics
Correct Answer
A. True
Explanation
The statement is true because a sampling distribution refers to the distribution of sample statistics, such as the mean or standard deviation, that would be obtained from repeated sampling of a population. It is a theoretical distribution because it is based on the assumption that the samples are drawn randomly and independently from the population. The sampling distribution allows us to make inferences about the population parameters based on the sample statistics.
17.
Central limit theorem is the distribution of sample averages tends to be normal regardless of the shape of the process distribution
Correct Answer
A. True
Explanation
The explanation for the given correct answer is that the central limit theorem states that when independent random variables are added, their sum tends toward a normal distribution, regardless of the shape of the original distribution. This means that even if the process distribution is not normal, the distribution of sample averages will become approximately normal as the sample size increases. Therefore, the statement that the distribution of sample averages tends to be normal regardless of the shape of the process distribution is true.
18.
Control chart is a time ordered plot of sample statistics, used to distinguish between random and nonrandom variablity
Correct Answer
A. True
Explanation
A control chart is a graphical tool that displays data points over time, allowing for the identification of patterns and trends. It helps to distinguish between random variation, which is expected and inherent in any process, and nonrandom variation, which indicates a specific cause or issue. By analyzing the plotted sample statistics, such as mean or range, control charts provide a visual representation of the process's performance and whether it is within acceptable limits. Therefore, the statement that a control chart is a time-ordered plot of sample statistics used to distinguish between random and nonrandom variability is true.
19.
Control limits is the dividing lines between random and nonrandom deviations from the mean of the distribution
Correct Answer
A. True
Explanation
The statement is true because control limits are used in statistical process control to determine whether a process is in a state of control or not. These limits are based on the mean and variation of the process and act as boundaries that define the expected range of random variation. If data points fall within these limits, it is considered to be random variation, indicating that the process is in control. However, if data points fall outside these limits, it suggests nonrandom variation, indicating that the process is out of control and may require investigation and corrective action.
20.
Type i error
Correct Answer
B. Concluding a process is not in control when it actually is
Explanation
Type I error refers to the incorrect rejection of a true null hypothesis in statistical hypothesis testing. In the context of this question, it means that concluding a process is not in control when it actually is. This means that a mistake has been made in determining that the process is not functioning properly or is out of control, when in reality it is functioning within acceptable limits. This error can lead to unnecessary interventions or changes in the process, which may not be required, resulting in wasted resources and time.
21.
Type ii error
Correct Answer
A. Concluding a process in control when it is not
Explanation
A type II error refers to the incorrect conclusion that a process is in control when it is actually not. This means that the analysis or testing conducted on the process fails to identify any issues or abnormalities, leading to the false belief that the process is functioning properly. This can be problematic as it may result in the continuation of a faulty process, leading to potential errors or defects in the future.
22.
Variables generate data that are NOT measured
Correct Answer
B. False
Explanation
variables generate data that ARE measured
23.
Mean control chart is the control chart used to monitor the central tendency of a process
Correct Answer
A. True
Explanation
The statement is true because a mean control chart is indeed used to monitor the central tendency of a process. It is a statistical tool that helps to analyze and track the average value of a process over time. By plotting the sample means on the control chart, any variations or shifts in the central tendency can be easily identified and corrective actions can be taken to maintain the desired process performance.
24.
Range control chart is used to monitor process dispersion
Correct Answer
A. True
Explanation
A range control chart is a statistical tool used to monitor the dispersion or variation in a process. By plotting the range of a sample over time, it helps to identify any changes or shifts in process variability. This allows for early detection of potential issues or outliers that may affect the quality of the output. Therefore, the statement that a range control chart is used to monitor process dispersion is true.
25.
P chart
Correct Answer
B. Control chart for attributes, used to monitor the proportion of defective items in a process
Explanation
The correct answer is control chart for attributes, used to monitor the proportion of defective items in a process. A p chart is a type of control chart that is specifically used to monitor the proportion of defective items in a process. It is commonly used in quality control to track the performance of a process over time and identify any trends or patterns in the proportion of defects. By monitoring the proportion of defects, organizations can take proactive measures to improve the process and reduce the number of defective items.
26.
C chart
Correct Answer
A. Control chart for attributes, used to monitor the number of defects per unit
Explanation
The c chart is a control chart for attributes that is used to monitor the number of defects per unit. It is particularly useful when the number of defects can vary widely between units. By plotting the number of defects per unit over time, the c chart helps identify any patterns or trends in the defect rates, allowing for timely corrective actions to be taken. This type of control chart is commonly used in manufacturing and quality control processes to ensure that defects are minimized and production remains within acceptable limits.
27.
Specification is a range of acceptable values established by engineering design or customer requirements
Correct Answer
A. True
Explanation
The statement is defining the term "specification" as a range of acceptable values that are determined either by engineering design or customer requirements. This implies that specifications are indeed a range of acceptable values, which makes the answer "true" correct.
28.
Process variability is natural or inherent variability in a process
Correct Answer
A. True
Explanation
The statement is true because process variability refers to the natural or inherent variability that occurs in a process. This means that even under controlled conditions, there will always be some level of variation in the outputs or outcomes of a process. This variability can be caused by various factors such as equipment limitations, environmental conditions, or human factors. It is important to understand and manage process variability in order to ensure consistent and reliable process performance.
29.
Process capability is the inherent variability of process output relative to the variation allowed by the design specification
Correct Answer
A. True
Explanation
Process capability refers to the ability of a process to consistently produce output that meets the design specifications. It measures the inherent variability of the process output in relation to the allowed variation defined by the design specifications. If the process capability is high, it indicates that the process is capable of producing output within the specified limits with minimal variation. Therefore, the given statement is true as it accurately defines process capability in terms of the relationship between process output variability and design specification limits.