Question 1

The process capability index measures the capability of the process to produce units whose dimensions fall outside the specification limits.

Accepted Answer

A) True 
 B)False  False

Question 2

Control charts used to determine if the process distribution standard deviation has changed are:

Accepted Answer

A)  and p charts. 
B)  p and R charts. 
C)  R and S charts. 
D)  S andcharts. 
A)  and p charts. 
B)  p and R charts. 
C)  R and S charts. 
D)  S andcharts. C

Question 3

If you change the control limits from $\pm$3 standard errors from the centerline to $\pm$2 standard deviations from the centerline,this ____________________ the probability of a Type I error and ____________________ the probability of a Type II error.

Accepted Answer

increases;decreases

Question 4

In designing a control chart,the statistician must select a sample size and a sampling frequency.These decisions are based on which factors:

Accepted Answer

A)  Cost of making Type I and Type II errors. 
B)  Length of the production run. 
C)  Typical change in the process distribution when the process goes out of control. 
D)  All of these choices are true. 
A)  Cost of making Type I and Type II errors. 
B)  Length of the production run. 
C)  Typical change in the process distribution when the process goes out of control. 
D)  All of these choices are true.

Question 5

A predictable change in operators for the day shift and night shift can create assignable variation called a cycle.

Accepted Answer

A) True 
 B)False

Question 6

A hypothesis test is used to determine whether there is sufficient evidence to infer that the process mean has changed.This means H0 is: the process is ____________________ control.

Accepted Answer

Question 7

Assembly Line
Random samples of 200 parts were taken on an assembly line every hour for the past 25 hours.The number of defective parts is shown in the accompanying table.
 $$\begin{array}{l}
\begin{array} { | l | l l l c l l l l l l l l l | } 
\hline \text { Sample } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 & 13 \
\hline \begin{array} { l } 
\text { Number af } \
\text { Defectives }
\end{array} & 5 & 2 & 4 & 10 & 2 & 6 & 8 & 2 & 0 & 5 & 12 & 11 & \mathbf { 8 } \
\hline
\end{array}\\
\begin{array} { | l | c c c c c c c c c c c c | } 
\hline \text { Sample } & 14 & 15 & 16 & 17 & 18 & 19 & 20 & 21 & 22 & 23 & 24 & 25 \
\hline \begin{array} { l } 
\text { Number of } \
\text { Defective5 }
\end{array} & 10 & 5 & 13 & 7 & 5 & 7 & 11 & 3 & 16 & 3 & 2 & 10 \
\hline
\end{array}
\end{array}$$
-{Assembly Line Narrative} Construct the p chart.

Accepted Answer

The answer of Assembly Line
Random samples of 200 parts were...

Question 8

Sample proportions that are less than the lower control limit indicate a change in the process that we would like to make permanent.

Accepted Answer

A) True 
 B)False

Question 9

To estimate the standard deviation of a process distribution,we calculate the sample variance for each sample collected.Then we compute the ____________________ standard deviation,denoted by S.

Accepted Answer

The answer of To estimate the standard deviation of a...

Question 10

When no point lies outside the control limits of a chart,we conclude that variation in the process is:

Accepted Answer

A)  caused by chance and there is not enough evidence to infer that the process is out of control. 
B)  caused by chance and there is enough evidence to infer that the process is out of control. 
C)  caused by assignable causes and there is enough evidence to infer that the process is under control. 
D)  caused by assignable causes and there is not enough evidence to infer that the process is out of control. 
A)  caused by chance and there is not enough evidence to infer that the process is out of control. 
B)  caused by chance and there is enough evidence to infer that the process is out of control. 
C)  caused by assignable causes and there is enough evidence to infer that the process is under control. 
D)  caused by assignable causes and there is not enough evidence to infer that the process is out of control.

Question 11

Samples Manufacturing
The mean of the sample means and the pooled standard deviation of 40 samples of size 5 taken from a production process under control are $\bar { x } = 518.7$ ,and S = 11.5,respectively.
-The p chart is an example of control charts for attributes.

Accepted Answer

A) True 
 B)False

Question 12

Variations in a process that are caused by specific events or factors that are frequently temporary and can usually be identified and eliminated are known as:

Accepted Answer

A)  chance variation. 
B)  common variation. 
C)  assignable variation. 
D)  All of these choices are true. 
A)  chance variation. 
B)  common variation. 
C)  assignable variation. 
D)  All of these choices are true.

Question 13

Assume a process has limits set at $\pm$2.5 standard errors from the centerline.The average run length (ARL)is 81.What does this mean?

Accepted Answer

When the process is under control,the @#LAT-DLM& c

Question 14

Assume that the control limits of an $\bar { x }$ chart are defined as 2.5 standard errors above and below the centerline.Calculate the probability that a sample mean falls outside the control limits when the process is in fact under control.

Accepted Answer

P = P (| z | > 2.5)=

Question 15

Fifty samples of size 1,000 were drawn from a manufacturing process and the number of defectives in each sample was counted.The mean sample proportion was .05.The centerline for the p chart is 50.

Accepted Answer

A) True 
 B)False

Question 16

The $\bar { x }$ chart helps with questions about whether the process is producing the correct or acceptable mean.

Accepted Answer

A) True 
 B)False

Question 17

A new machine can cause a change in the mean of a process distribution.This is a result of a level shift.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following is an example of assignable variation in a process?

Accepted Answer

A)  The valve on the machine that fills paint cans has malfunctioned. 
B)  The operator of the paint filling machine experiences fatigue during his shift. 
C)  A temperature or humidity change has occurred in the factory. 
D)  All of these choices are true. 
A)  The valve on the machine that fills paint cans has malfunctioned. 
B)  The operator of the paint filling machine experiences fatigue during his shift. 
C)  A temperature or humidity change has occurred in the factory. 
D)  All of these choices are true.

Question 19

We construct a p chart to track the ____________________ of defective units in a series of samples.

Accepted Answer

proportion

Question 20

The mean of the sample means and the pooled standard deviation of 40 samples of size 9 taken from a production process under control are $\bar{\bar { x }} = 420$ ,and S = 12,respectively.The lower control limit and the upper control limit of the 3-sigma $\bar { x }$ chart are 408 and 432,respectively.

Accepted Answer

A) True 
 B)False

Exam 21: Statistical Process Control

The process capability index measures the capability of the process to produce units whose dimensions fall outside the specification limits.

Control charts used to determine if the process distribution standard deviation has changed are:

If you change the control limits from ±\pm± 3 standard errors from the centerline to ±\pm± 2 standard deviations from the centerline,this ____________________ the probability of a Type I error and ____________________ the probability of a Type II error.

In designing a control chart,the statistician must select a sample size and a sampling frequency.These decisions are based on which factors:

A predictable change in operators for the day shift and night shift can create assignable variation called a cycle.

A hypothesis test is used to determine whether there is sufficient evidence to infer that the process mean has changed.This means H0 is: the process is ____________________ control.

Sample proportions that are less than the lower control limit indicate a change in the process that we would like to make permanent.

To estimate the standard deviation of a process distribution,we calculate the sample variance for each sample collected.Then we compute the ____________________ standard deviation,denoted by S.

When no point lies outside the control limits of a chart,we conclude that variation in the process is:

Samples Manufacturing The mean of the sample means and the pooled standard deviation of 40 samples of size 5 taken from a production process under control are xˉ=518.7\bar { x } = 518.7xˉ=518.7 ,and S = 11.5,respectively. -The p chart is an example of control charts for attributes.

Variations in a process that are caused by specific events or factors that are frequently temporary and can usually be identified and eliminated are known as:

Assume a process has limits set at ±\pm± 2.5 standard errors from the centerline.The average run length (ARL)is 81.What does this mean?

Assume that the control limits of an xˉ\bar { x }xˉ chart are defined as 2.5 standard errors above and below the centerline.Calculate the probability that a sample mean falls outside the control limits when the process is in fact under control.

Fifty samples of size 1,000 were drawn from a manufacturing process and the number of defectives in each sample was counted.The mean sample proportion was .05.The centerline for the p chart is 50.

The xˉ\bar { x }xˉ chart helps with questions about whether the process is producing the correct or acceptable mean.

A new machine can cause a change in the mean of a process distribution.This is a result of a level shift.

Which of the following is an example of assignable variation in a process?

We construct a p chart to track the ____________________ of defective units in a series of samples.

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

A: Numerical Descriptive Techniques

B: Numerical Descriptive Techniques

C: Numerical Descriptive Techniques

Data Collection and Sampling

Probability

A: Random Variables and Discrete Probability Distributions

B: Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

A: Simple Linear Regression and Correlation

B: Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analysis and Forecasting

Decision Analysis

Conclusion

Filters

If you change the control limits from $\pm$ 3 standard errors from the centerline to $\pm$ 2 standard deviations from the centerline,this the probability of a Type I error and the probability of a Type II error.

A hypothesis test is used to determine whether there is sufficient evidence to infer that the process mean has changed.This means H₀ is: the process is ____________________ control.

Samples Manufacturing The mean of the sample means and the pooled standard deviation of 40 samples of size 5 taken from a production process under control are $\bar { x } = 518.7$ ,and S = 11.5,respectively. -The p chart is an example of control charts for attributes.

Assume a process has limits set at $\pm$ 2.5 standard errors from the centerline.The average run length (ARL)is 81.What does this mean?

Assume that the control limits of an $\bar { x }$ chart are defined as 2.5 standard errors above and below the centerline.Calculate the probability that a sample mean falls outside the control limits when the process is in fact under control.

The $\bar { x }$ chart helps with questions about whether the process is producing the correct or acceptable mean.