ASQ Study
Which of the following is a disadvantage of pre-control charts?
a. They do not provide information on how to reduce variability in a
process.
b. They cannot determine if a product being produced is centered between
the tolerances during initial operation setup.
c. They are difficult to interpret.
d. They can be used for processes with a capability ratio less than 1. - answer(A)
Pre-control charts do not provide information on how variability can be reduced or how
to bring a process into control. They should only be used for processes with a capability
ration greater than one. Poor capability in a pre-control chart will indicate that
assignable causes are present when in fact there are no assignable causes of variation.
Small sample sizes in a pre-control chart will reduce the cart's ability to detect moderate
to large shifts. Pre-control charts are useful in initial setup operations to determine
whether a process is centered between the tolerances.
Which of the following is considered attribute data?
a. Customer wait time
b. Number of filing errors
c. Costs of processing applications
d. Thickness of a component - answer(B)
Attribute data is the term used to describe discrete data in quality control. Wait time,
processing costs, and thickness can each be measured on a continuous scale. The
number of filing errors can only take on a countable set of numbers, and is considered
discrete, or attribute, data.
A population. has a distribution with a mean 24 and standard deviation 5.5. What is the
approximate standard deviation of the sampling distribution of the sample mean if
random samples of size 32 are taken?
a. 5.5
b . 5.5/32
c. 5.5/√24
d . 5.5/√32 - answer(D)
The central limit theorem states that if the sample size n is sufficiently large, then the
sample mean x̄ follows approximately a normal distribution with mean μ↓x̄ = μ and
standard deviation σ↓x̄ = σ/√n.
In this case, μ = 24, σ = 5.5 and n = 32. Therefore, σ↓x̄ = 5.5/√32
A control chart monitoring the viscosity of a product shows that a particular process is
out of control. What should the process operator do?
a. Attempt to fix the problem on their own.
b. Follow the reaction plan detailed in the control plan of the process.
,c. Brainstorm to determine the cause of the problem.
d. Nothing; the process will stabilize on its own. - answer(B)
Control plans include detailed reaction plans that should be followed when the control
method detects a problem in the process. The reaction plan details the steps the
operator should take when the process has a problem .
An x̄ and R chart was prepared for an operation using 25 samples with four pieces in
each sample. x̅̅ was found to be 26.75 and R¯ was 8.10. During production, a sample of
four was taken and the pieces measured 20, 29, 40, and 25. At the time this sample
was taken
a. both the average and range were within the control limits.
b. neither the average nor range were within the control limits.
c. only the average was outside the control limits.
d. only the range was outside the control limits.
(R¯ is R with a bar on top) - answer(D)
https://docs.google.com/document/d/
1n4TBe4uMD4IjlaTu0g31oHdZweuecVrXqgHt2ClUdck/edit?usp=sharing
Suppose that the p-value of a hypothesis test on μ1 - μ2 is 0.23. What conclusions can
be made (use significance level 10%)?
a. Reject Ho, conclude that the two means are the same.
b. Reject Ho, conclude that the two means are not the same.
c. Do not reject Ho, Conclude that the two means are the same.
process.
d. Do not reject Ho, Conclude that the two means are not the same. - answer(C)
𝛼 = 0.10 and p-value = 0.23. Using the p-value approach to hypothesis testing, if the p-
value < 𝛼, we do not reject Ho. Since 0.23 > 0.10, we do not reject Ho and conclude that
the two means are the same.
Which phase of the corrective action cycle helps prevent problem backsliding?
a. Problem identification
b. Correction
c. Recurrence control
d. Effectiveness assessment - answer(C)
In the problem identification phase, the team identifies sources for improvement and
develops a clear problem statement. In the correction phase, the team develops
feasible solutions to the problem and recommends the best choice to implement. In the
recurrence control phase, the team standardizes the solution to ensure that the problem
does not reoccur and prevent backsliding. Finally, in the effectiveness assessment
phase, the team continues monitoring the process to identify additional opportunities for
improvement.
A team were investigated the number of patient falls in a hospital. Fifty-six patients were
randomly selected. Out of the 56 patients, there were six recorded patient falls. Using
, this information, construct a 90% confidence interval on the true proportion of patient
falls in this hospital.
a. (-0.4016, 0.6158)
b. (0, 0.6158)
c. (0.0006, 0.2136)
d. (0.0391, 0.1751) - answer(D)
In this problem, a "success" is a patient fall. Therefore, x = 6 and n = 56.
We are 90% confident that the true proportion of patient falls in the hospital is between
3.91% and 17.5l%.
A gage R&R study was preformed for a process with 10 parts, tow operators, and three
replicates. The x̄ chart below displays information about the gage
capability. What conclusions can be drawn from this control chart?
chart:
https://docs.google.com/document/d/1BXztHByUWC7ZOGKGoOzBHALdvv3Oy7V0zO
NooRHJzgM/edit?usp=sharing
a. The gage is capable of distinguishing between parts.
b. There is a significant difference between operators.
c. The chart reflects variability related to gage reproducibility.
d. The gage is not capable of distinguishing between parts. - answer(D) The x̄ control
chart reflects within-sample variability, which is related to gage repeatability. If the gage
is capable, then it should be able to distinguish between parts. Therefore, we would
expect many of the points to plot outside the control limits. In this case, most of the
points are within the control limits; this indicates that the gage cannot distinguish
between parts.
Find the probability that Z, the standard normal distribution, lies between -1.02 and 0.58.
a. 0.5651
b. 0.1539
c. 0.7190
d. 0.4349 - answer(A)
From the properties of the cumulative distribution function,
P(a < Z <b) = P(Z < b) - P(Z < a). Therefore, using a standard normal table,
P(-1.02 < Z < 0.58) = P(Z < 0.58) - P(Z < -1.02) = 0.7190- 0.1539 = 0.5651.
https://docs.google.com/document/d/
1XFypHry8N1U6pZpy8pMo2qbvTfTlku5dOCo4VqySry4/edit?usp=sharing
The date of a customer's visit to a store is on which measurement scale?
a. Nominal
b. Ordinal
c. Interval
d. Ratio - answer(C)
A date is on an interval scale. There are meaningful differences between two dates, but
there is no absolute zero. Dates can be added or subtracted. For example, you can
Which of the following is a disadvantage of pre-control charts?
a. They do not provide information on how to reduce variability in a
process.
b. They cannot determine if a product being produced is centered between
the tolerances during initial operation setup.
c. They are difficult to interpret.
d. They can be used for processes with a capability ratio less than 1. - answer(A)
Pre-control charts do not provide information on how variability can be reduced or how
to bring a process into control. They should only be used for processes with a capability
ration greater than one. Poor capability in a pre-control chart will indicate that
assignable causes are present when in fact there are no assignable causes of variation.
Small sample sizes in a pre-control chart will reduce the cart's ability to detect moderate
to large shifts. Pre-control charts are useful in initial setup operations to determine
whether a process is centered between the tolerances.
Which of the following is considered attribute data?
a. Customer wait time
b. Number of filing errors
c. Costs of processing applications
d. Thickness of a component - answer(B)
Attribute data is the term used to describe discrete data in quality control. Wait time,
processing costs, and thickness can each be measured on a continuous scale. The
number of filing errors can only take on a countable set of numbers, and is considered
discrete, or attribute, data.
A population. has a distribution with a mean 24 and standard deviation 5.5. What is the
approximate standard deviation of the sampling distribution of the sample mean if
random samples of size 32 are taken?
a. 5.5
b . 5.5/32
c. 5.5/√24
d . 5.5/√32 - answer(D)
The central limit theorem states that if the sample size n is sufficiently large, then the
sample mean x̄ follows approximately a normal distribution with mean μ↓x̄ = μ and
standard deviation σ↓x̄ = σ/√n.
In this case, μ = 24, σ = 5.5 and n = 32. Therefore, σ↓x̄ = 5.5/√32
A control chart monitoring the viscosity of a product shows that a particular process is
out of control. What should the process operator do?
a. Attempt to fix the problem on their own.
b. Follow the reaction plan detailed in the control plan of the process.
,c. Brainstorm to determine the cause of the problem.
d. Nothing; the process will stabilize on its own. - answer(B)
Control plans include detailed reaction plans that should be followed when the control
method detects a problem in the process. The reaction plan details the steps the
operator should take when the process has a problem .
An x̄ and R chart was prepared for an operation using 25 samples with four pieces in
each sample. x̅̅ was found to be 26.75 and R¯ was 8.10. During production, a sample of
four was taken and the pieces measured 20, 29, 40, and 25. At the time this sample
was taken
a. both the average and range were within the control limits.
b. neither the average nor range were within the control limits.
c. only the average was outside the control limits.
d. only the range was outside the control limits.
(R¯ is R with a bar on top) - answer(D)
https://docs.google.com/document/d/
1n4TBe4uMD4IjlaTu0g31oHdZweuecVrXqgHt2ClUdck/edit?usp=sharing
Suppose that the p-value of a hypothesis test on μ1 - μ2 is 0.23. What conclusions can
be made (use significance level 10%)?
a. Reject Ho, conclude that the two means are the same.
b. Reject Ho, conclude that the two means are not the same.
c. Do not reject Ho, Conclude that the two means are the same.
process.
d. Do not reject Ho, Conclude that the two means are not the same. - answer(C)
𝛼 = 0.10 and p-value = 0.23. Using the p-value approach to hypothesis testing, if the p-
value < 𝛼, we do not reject Ho. Since 0.23 > 0.10, we do not reject Ho and conclude that
the two means are the same.
Which phase of the corrective action cycle helps prevent problem backsliding?
a. Problem identification
b. Correction
c. Recurrence control
d. Effectiveness assessment - answer(C)
In the problem identification phase, the team identifies sources for improvement and
develops a clear problem statement. In the correction phase, the team develops
feasible solutions to the problem and recommends the best choice to implement. In the
recurrence control phase, the team standardizes the solution to ensure that the problem
does not reoccur and prevent backsliding. Finally, in the effectiveness assessment
phase, the team continues monitoring the process to identify additional opportunities for
improvement.
A team were investigated the number of patient falls in a hospital. Fifty-six patients were
randomly selected. Out of the 56 patients, there were six recorded patient falls. Using
, this information, construct a 90% confidence interval on the true proportion of patient
falls in this hospital.
a. (-0.4016, 0.6158)
b. (0, 0.6158)
c. (0.0006, 0.2136)
d. (0.0391, 0.1751) - answer(D)
In this problem, a "success" is a patient fall. Therefore, x = 6 and n = 56.
We are 90% confident that the true proportion of patient falls in the hospital is between
3.91% and 17.5l%.
A gage R&R study was preformed for a process with 10 parts, tow operators, and three
replicates. The x̄ chart below displays information about the gage
capability. What conclusions can be drawn from this control chart?
chart:
https://docs.google.com/document/d/1BXztHByUWC7ZOGKGoOzBHALdvv3Oy7V0zO
NooRHJzgM/edit?usp=sharing
a. The gage is capable of distinguishing between parts.
b. There is a significant difference between operators.
c. The chart reflects variability related to gage reproducibility.
d. The gage is not capable of distinguishing between parts. - answer(D) The x̄ control
chart reflects within-sample variability, which is related to gage repeatability. If the gage
is capable, then it should be able to distinguish between parts. Therefore, we would
expect many of the points to plot outside the control limits. In this case, most of the
points are within the control limits; this indicates that the gage cannot distinguish
between parts.
Find the probability that Z, the standard normal distribution, lies between -1.02 and 0.58.
a. 0.5651
b. 0.1539
c. 0.7190
d. 0.4349 - answer(A)
From the properties of the cumulative distribution function,
P(a < Z <b) = P(Z < b) - P(Z < a). Therefore, using a standard normal table,
P(-1.02 < Z < 0.58) = P(Z < 0.58) - P(Z < -1.02) = 0.7190- 0.1539 = 0.5651.
https://docs.google.com/document/d/
1XFypHry8N1U6pZpy8pMo2qbvTfTlku5dOCo4VqySry4/edit?usp=sharing
The date of a customer's visit to a store is on which measurement scale?
a. Nominal
b. Ordinal
c. Interval
d. Ratio - answer(C)
A date is on an interval scale. There are meaningful differences between two dates, but
there is no absolute zero. Dates can be added or subtracted. For example, you can
