ISDS 3115 Test 2 – Complete Study Guide &
Practice Questions 2025/26 -With 100% Verified
Answers – Rated A+, Success Guaranteed
If a sample of items is taken and the mean of the sample is outside the control limits, the
process is:
A) likely out of control and the cause should be investigated.
B) in control, but not capable of producing within the established control limits.
C) within the established control limits with only natural causes of variation.
D) monitored closely to see if the next sample mean will also fall outside the control limits.
E) producing high quality products. - ...answera
*The causes of variation in statistical process control are:*
A) cycles, trends, seasonality, and random variations.
B) producer's causes and consumer's causes.
C) mean and range.
D) natural causes and assignable causes.
E) Type I and Type II. - ...answerd
*Natural variations:*
A) affect almost every production process.
B) are the many sources of variation that occur when a process is under control.
C) when grouped, form a pattern, or distribution.
D) are tolerated, within limits, when a process is under control.
E) All of the above are true. - ...answerE) All of the above are true.
,*Natural variations:*
A) are variations that are to be identified and investigated.
B) are variations that can be traced to a specific cause.
C) are the same as assignable variations.
D) lead to occasional false findings that processes are out of control.
E) play no role in statistical process control. - ...answerd
*Assignable variation:*
A) is a sign that a process is under control.
B) is to be identified and investigated.
C) is the same as random variation.
D) is variation that cannot be traced to a specific cause.
E) leads to a steep OC curve. - ...answerb
Control charts for variables are based on data that come from:
A) acceptance sampling.
B) individual items.
C) averages of small samples.
D) averages of large samples.
E) the entire lot. - ...answerc
The purpose of an x-bar chart is to determine whether there has been a:
A) change in the dispersion of the process output.
B) change in the percent defective in a sample.
C) change in the central tendency of the process output.
D) change in the number of defects in a sample.
,E) change in the AOQ. - ...answerc
*The number of defects after a hotel room cleaning (sheets not straight, smears on mirror,
missed debris on carpet, etc) should be measured using what type of control chart?*
A) x-bar chart
B) R-chart
C) p-chart
D) c-chart
E) either x-bar chart or R chart - ...answerd
*The number of late insurance claim payouts per 100 should be measured with what type of
control chart?*
A) x-bar chart
B) R-chart
C) p-chart
D) c-chart
E) either p-chart or c-chart - ...answerc
The upper and lower limits for diving ring diameters made by John's Swimming Co. are 40 and
39 cm., respectively. John took 11 samples with the following average diameters (39, 39.1, 39.2,
39.3, 39.4, 39.5 39.6, 39.7, 39.8, 39.9, 40). Is the process in control?
A) Yes, no diameters exceeded the control limits.
B) No, some diameters exceeded the control limits.
C) No, there is a distinguishable pattern to the samples.
D) No, the range is not in control.
E) There is not enough information to make a decision. - ...answerc
, *Red Top Cab Company receives multiple complaints per day about driver behavior. Over 9 days
the owner recorded the number of calls to be 3, 0, 8, 9, 6, 7, 4, 9, and 8. What is the upper
control limit for the 3-sigma c-chart?*
A) 13.35
B) 8.45
C) 24.00
D) 0.00
E) 9.03 - ...answera
A process that is assumed to be in control with limits of 89 ± 2 had sample averages for the x-
bar chart of the following: 87.1, 87, 87.2, 89, 90, 88.5, 89.5, and 88. Is the process in control?
A) Yes.
B) No, one or more averages exceeded the limits.
C) Not enough information to tell.
D) No, there is a distinguishable trend.
E) No, two or more consecutive points are very near the lower (or upper) limit. - ...answere
Ten samples of a process measuring the number of returns per 100 receipts were taken for a
local retail store. The number of returns were 10, 9, 11, 7, 3, 12, 8, 4, 6, and 11. Find the
standard deviation of the sampling distribution for the p-bar chart.
A) There is not enough information to answer the question.
B) .081
C) 8.1
D) .0273
E) .0863 - ...answerd
An x-bar control chart was examined and no data points fell outside of the limits. Can this
process be considered in control?
Practice Questions 2025/26 -With 100% Verified
Answers – Rated A+, Success Guaranteed
If a sample of items is taken and the mean of the sample is outside the control limits, the
process is:
A) likely out of control and the cause should be investigated.
B) in control, but not capable of producing within the established control limits.
C) within the established control limits with only natural causes of variation.
D) monitored closely to see if the next sample mean will also fall outside the control limits.
E) producing high quality products. - ...answera
*The causes of variation in statistical process control are:*
A) cycles, trends, seasonality, and random variations.
B) producer's causes and consumer's causes.
C) mean and range.
D) natural causes and assignable causes.
E) Type I and Type II. - ...answerd
*Natural variations:*
A) affect almost every production process.
B) are the many sources of variation that occur when a process is under control.
C) when grouped, form a pattern, or distribution.
D) are tolerated, within limits, when a process is under control.
E) All of the above are true. - ...answerE) All of the above are true.
,*Natural variations:*
A) are variations that are to be identified and investigated.
B) are variations that can be traced to a specific cause.
C) are the same as assignable variations.
D) lead to occasional false findings that processes are out of control.
E) play no role in statistical process control. - ...answerd
*Assignable variation:*
A) is a sign that a process is under control.
B) is to be identified and investigated.
C) is the same as random variation.
D) is variation that cannot be traced to a specific cause.
E) leads to a steep OC curve. - ...answerb
Control charts for variables are based on data that come from:
A) acceptance sampling.
B) individual items.
C) averages of small samples.
D) averages of large samples.
E) the entire lot. - ...answerc
The purpose of an x-bar chart is to determine whether there has been a:
A) change in the dispersion of the process output.
B) change in the percent defective in a sample.
C) change in the central tendency of the process output.
D) change in the number of defects in a sample.
,E) change in the AOQ. - ...answerc
*The number of defects after a hotel room cleaning (sheets not straight, smears on mirror,
missed debris on carpet, etc) should be measured using what type of control chart?*
A) x-bar chart
B) R-chart
C) p-chart
D) c-chart
E) either x-bar chart or R chart - ...answerd
*The number of late insurance claim payouts per 100 should be measured with what type of
control chart?*
A) x-bar chart
B) R-chart
C) p-chart
D) c-chart
E) either p-chart or c-chart - ...answerc
The upper and lower limits for diving ring diameters made by John's Swimming Co. are 40 and
39 cm., respectively. John took 11 samples with the following average diameters (39, 39.1, 39.2,
39.3, 39.4, 39.5 39.6, 39.7, 39.8, 39.9, 40). Is the process in control?
A) Yes, no diameters exceeded the control limits.
B) No, some diameters exceeded the control limits.
C) No, there is a distinguishable pattern to the samples.
D) No, the range is not in control.
E) There is not enough information to make a decision. - ...answerc
, *Red Top Cab Company receives multiple complaints per day about driver behavior. Over 9 days
the owner recorded the number of calls to be 3, 0, 8, 9, 6, 7, 4, 9, and 8. What is the upper
control limit for the 3-sigma c-chart?*
A) 13.35
B) 8.45
C) 24.00
D) 0.00
E) 9.03 - ...answera
A process that is assumed to be in control with limits of 89 ± 2 had sample averages for the x-
bar chart of the following: 87.1, 87, 87.2, 89, 90, 88.5, 89.5, and 88. Is the process in control?
A) Yes.
B) No, one or more averages exceeded the limits.
C) Not enough information to tell.
D) No, there is a distinguishable trend.
E) No, two or more consecutive points are very near the lower (or upper) limit. - ...answere
Ten samples of a process measuring the number of returns per 100 receipts were taken for a
local retail store. The number of returns were 10, 9, 11, 7, 3, 12, 8, 4, 6, and 11. Find the
standard deviation of the sampling distribution for the p-bar chart.
A) There is not enough information to answer the question.
B) .081
C) 8.1
D) .0273
E) .0863 - ...answerd
An x-bar control chart was examined and no data points fell outside of the limits. Can this
process be considered in control?
