Question 1

TABLE 17-2
A political pollster randomly selects a sample of 100 voters each day for 8 successive days and asks how many will vote for the incumbent. The pollster wishes to construct a p chart to see if the percentage favoring the incumbent candidate is too erratic.
 
-Referring to Table 17-2, what is the numerical value of the center line for the p chart?

Accepted Answer

The center line for a p chart is calculated using the overall sample proportion, which is the total number of voters favoring the incumbent divided by the total number of voters sampled. In this case, the total number favoring the incumbent over the 8 days is 420, and the total number sampled is 800. Therefore, the overall sample proportion is 420/800 = 0.525. The center line for the p chart is then calculated as the overall sample proportion, so the answer is B) 0.56 (which is 0.525 rounded to two decimal places).

Question 2

Which of the following is not one of Deming's 14 points?

Accepted Answer

Deming's 14 points emphasize the need to focus on continuous improvement, teamwork, communication, and quality. However, awarding business on the basis of price tag alone conflicts with Deming's philosophy of valuing long-term relationships with suppliers who are committed to quality and improvement.

Question 3

Which of the following is not one of Deming's 14 points?

Accepted Answer

Deming advocated for eliminating mass inspection, believing that it was not an effective way to improve quality and actually created more costs and inefficiencies.

Question 4

Once the control limits are set for a control chart, one attempts to

Accepted Answer

Setting control limits for a control chart is done to monitor a process over time. Once they are set, one attempts to discern patterns in the values over time and determine whether any points fall outside the control limits. Therefore, both options A and B are correct.

Question 5

Which of the following situations suggests a process that appears to be operating out of statistical control?

Accepted Answer

All the described situations suggest a process that is operating out of statistical control. Consecutive points consistently above or below the center line, points falling outside the lower control limit, and several points outside the upper control limit all indicate potential issues with process stability or control.

Question 6

One of the morals of the red bead experiment is:

Accepted Answer

The experiment emphasizes that variation is inherent in any system, and that it is the system itself rather than individual performance that primarily determines outcomes. Additionally, the experiment highlights the importance of management's role in improving systems and reducing variation. Therefore, all three options (A, B, and C) are correct and represent important morals of the experiment.

Question 7

The Shewhart-Deming cycle plays an important role in which of the following Deming's 14 points for management?

Accepted Answer

The Shewhart-Deming cycle, also known as the PDCA cycle (Plan, Do, Check, Act), is a model for continuous improvement. It is specifically referenced in Deming's 14th point, which emphasizes the need for organizations to create constancy of purpose for improvement of products and services. By implementing the PDCA cycle, organizations can continually plan, test, and refine their processes, products, and services to achieve continual improvement.

Question 8

TABLE 17-1
A local newspaper has 10 delivery boys who each deliver the morning paper to 50 customers every day. The owner decides to record the number of papers delivered on time for a 10-day period and construct a p chart to see whether the percentage is too erratic.
 
-Referring to Table 17-1, what is the numerical value of the lower control limit for the p chart?

Accepted Answer

The answer of TABLE 17-1
A local newspaper has 10 delivery...

Question 9

TABLE 17-1
A local newspaper has 10 delivery boys who each deliver the morning paper to 50 customers every day. The owner decides to record the number of papers delivered on time for a 10-day period and construct a p chart to see whether the percentage is too erratic.
 
-Referring to Table 17-1, what is the numerical value of the center line for the p chart?

Accepted Answer

The answer of TABLE 17-1
A local newspaper has 10 delivery...

Question 10

TABLE 17-1
A local newspaper has 10 delivery boys who each deliver the morning paper to 50 customers every day. The owner decides to record the number of papers delivered on time for a 10-day period and construct a p chart to see whether the percentage is too erratic.
 
-Referring to Table 17-1, what is the numerical value of the upper control limit for the p chart?

Accepted Answer

The answer of TABLE 17-1
A local newspaper has 10 delivery...

Question 11

The principal focus of the control chart is the attempt to separate special or assignable causes of variation from common causes of variation. What cause of variation can be reduced only by changing the system?

Accepted Answer

Common causes of variation cannot be completely eliminated, but can only be reduced by changing the system. Special or assignable causes of variation are caused by individual events or occurrences, which can be identified and eliminated, while common causes of variation are inherent in the system and require systemic changes to minimize their impact. Total causes include both common and special causes of variation.

Question 12

TABLE 17-1
A local newspaper has 10 delivery boys who each deliver the morning paper to 50 customers every day. The owner decides to record the number of papers delivered on time for a 10-day period and construct a p chart to see whether the percentage is too erratic.
 
-Referring to Table 17-1, which expression best characterizes the p chart?

Accepted Answer

The p chart is used to monitor the proportion of items in a sample that have a certain characteristic (in this case, papers delivered on time). The chart is used to determine whether the process is in control (meaning it is stable and predictable) or out of control (meaning it is unstable and producing erratic results). Since the chart shows no obvious cycles or trends, and there are no individual outliers that stand out, the best choice is C, in-control.

Question 13

The control chart

Accepted Answer

The control chart focuses on the time dimension of a system, captures the natural variability in the system, and can be used for categorical, discrete, or continuous variables. Therefore, all of the above options are correct.

Question 14

Which of the following is not part of the Shewhart-Deming cycle?

Accepted Answer

The Shewhart-Deming cycle, also known as the PDCA cycle, consists of four stages: Plan, Do, Check, and Act. React is not included as a separate stage in the cycle.

Question 15

Which of the following situations suggests a process that appears to be operating in a state of statistical control?

Accepted Answer

Option B describes a process that is operating in a state of statistical control, as there are no points falling outside the control limits and no discernible patterns on the chart. Options A and C both suggest a process that is out of control, as there are consecutive points above or below the center line, or points falling outside the control limits.

Question 16

Variation due to the inherent variability in a system of operation is called

Accepted Answer

Variation due to inherent variability in a system of operation is referred to as common or chance causes of variation. Special causes are due to specific events or circumstances that can be identified and eliminated or controlled. Explained variation refers to the portion of variability in a process that can be attributed to known causes, while the standard deviation is a measure of the amount of variation in a process.

Question 17

Variation signaled by individual fluctuations or patterns in the data is called

Accepted Answer

Special or assignable causes are individual fluctuations or patterns in the data that indicate variation. These causes can be identified and eliminated to improve the consistency and quality of the data. Common or chance causes, on the other hand, are natural variations in the data that cannot be eliminated and must be accounted for in statistical analysis. Explained variation refers to the portion of the total variance in the data that can be explained or attributed to specific factors, while the standard deviation measures the amount of variation or dispersion in the data.

Question 18

A process is said to be out of control if

Accepted Answer

Both options A and B indicate that a process is out of control. Option A refers to a single point falling outside of the control limits, while option B refers to a shift in the process mean (eight consecutive points above or below the center line). Therefore, either option A or option B can indicate that a process is out of control.

Question 19

TABLE 17-2
A political pollster randomly selects a sample of 100 voters each day for 8 successive days and asks how many will vote for the incumbent. The pollster wishes to construct a p chart to see if the percentage favoring the incumbent candidate is too erratic.
 
-Referring to Table 17-2, what is the numerical value of the lower control limit for the p chart?

Accepted Answer

To calculate the lower control limit for a p chart, we use the formula:

LCL = p - 3√(p(1-p)/n)

where p is the overall proportion of votes favoring the incumbent, and n is the sample size (100).

From Table 17-2, we see that the overall proportion of votes favoring the incumbent is 353/800, or 0.44125. Plugging this value into the formula, we get:

LCL = 0.44125 - 3√(0.44125(1-0.44125)/100) ≈ 0.408

Therefore, the numerical value of the lower control limit for the p chart is 0.408, which corresponds to choice (B).

Question 20

Which famous statistician developed the 14 Points of Quality?

Accepted Answer

The 14 Points of Quality were developed by W. Edwards Deming, a famous statistician known for his contributions to quality management in Japan after World War II.

Quiz 17: Statistical Applications in Quality Management

Which of the following is not one of Deming's 14 points?

Which of the following is not one of Deming's 14 points?

Once the control limits are set for a control chart, one attempts to

Which of the following situations suggests a process that appears to be operating out of statistical control?

One of the morals of the red bead experiment is:

The Shewhart-Deming cycle plays an important role in which of the following Deming's 14 points for management?

The principal focus of the control chart is the attempt to separate special or assignable causes of variation from common causes of variation. What cause of variation can be reduced only by changing the system?

The control chart

Which of the following is not part of the Shewhart-Deming cycle?

Which of the following situations suggests a process that appears to be operating in a state of statistical control?

Variation due to the inherent variability in a system of operation is called

Variation signaled by individual fluctuations or patterns in the data is called

A process is said to be out of control if

Which famous statistician developed the 14 Points of Quality?