51) Which of the following is true of nonrandom variation?
A) It is uncontrollable.
B) It is centered on a mean.
C) It occurs with a somewhat consistent amount of dispersion.
D) It results from a shift in a process mean or some unexpected occurrence.
E) It results in a process that is repeatable.
52) Process ________ means that the variation we observe in the process is random variation and
not nonrandom variation.
A) optimization
B) capability
C) control
D) variability
E) stability
53) Process stability means that the variation we observe in the process is ________ variation.
A) abnormal
B) specific
C) random
D) systematic
E) nonrandom
54) Nonrandom variation is centered on a mean and occurs with a consistent amount of
dispersion.
55) Random variation is also referred to as uncontrollable variation.
56) Random variation results from an event such as a shift in a process mean or some unexpected
occurrence.
57) Nonrandom variation results in a process that is not repeatable.
58) Process stability means that the variation observed in the process is nonrandom variation and
not random variation.
59) What is the difference between random and nonrandom variation?
60) The ________ is a process chart used to monitor the average of the characteristic being
measured.
A) chart
B) R chart
C) c chart
D) p chart
E) MR chart
61) The ________ chart is used in monitoring process dispersion.
A) chart
B) c chart
C) p chart
D) R chart
E) X chart
62) A(n) ________ is used when data are hypergeometrically distributed.
A) p chart
B) u chart
C) c chart
D) h chart
E) g chart
63) The ________ reflects a population distribution.
A) p chart
B) s chart
C) u chart
D) X chart
E) R chart
64) Although charts generally are preferred for variables data, sometimes it is too time
consuming or inconvenient to compute subgroup averages. In these cases, a(n) ________ is used.
A) median chart
B) X chart
C) p chart
D) s chart
E) standard deviation chart
65) The ________ is often used where variation in a process is small.
A) s chart
B) X chart
C) np chart
D) u chart
E) c chart
66) ________ are often used in monitoring the production of silicon chips for computers.
A) X charts
B) c charts
C) np charts
D) R charts
E) s charts
67) A g chart is useful when data are hypergeometrically distributed.
68) X chart limits are control limits and not natural limits.
69) If it is too time consuming or inconvenient to compute subgroup averages, a median chart
should be used.
70) The s chart is often used where variation in a process is large.
71) Describe the purpose of an s chart.
72) Describe x charts and R charts. List and describe the basic components of each.
73) ________ are tools for monitoring process variation.
A) Pareto charts
B) Control charts
C) Histograms
D) Scatter diagrams
E) Cause-and-effect diagrams
74) A(n) ________ is a continuous measurement such as weight, height, or volume.
A) variable
B) attribute
C) paradigm
D) criterion
E) element
75) A(n) ________ is an either-or-situation resulting from a binomial process.
A) variable
B) paradigm
C) criterion
D) attribute
E) element
76) Which of the following is an example of a variables chart?
A) u chart
B) c chart
C) np chart
D) p chart
E) X chart
77) Which of the following is an example of an attributes chart?
A) s chart
B) R chart
C) p chart
D) MR chart
E) X chart
78) What is the first step in developing process control charts?
A) Identify critical product characteristics.
B) Select the appropriate process control chart.
C) Determine whether the critical product characteristic is a variable or an attribute.
D) Identify critical operations in the process.
E) Establish the control limits.
79) Process population average, mean, range, moving range, and standard deviation are examples
of ________.
A) attributes
B) variables
C) elements
D) criteria
E) paradigms
80) Proportion defective, number defective, number nonconforming in a consistent sample space,
and number defects per unit are examples of ________.
A) criteria
B) paradigms
C) elements
D) variables
E) attributes
81) What is the lower limit of R for sample sizes less than or equal to six?
A) -1
B) 6
C) 0
D) -6
E) 1
82) The ________ is used for monitoring variables and measurement on a continuous scale.
A) cusum chart
B) c chart
C) X chart
D) np chart
E) moving average chart
83) The ________ uses past information to predict what the next process outcome will be.
A) np chart
B) u chart
C) moving average chart
D) cusum chart
E) p chart
84) The ________ is used to identify slight but sustained shifts in a universe where there is no
independence between observations.
A) cusum chart
B) moving average chart
C) s chart
D) np chart
E) R chart
85) Statistical process control charts are tools for monitoring process variation.
86) An attribute is a continuous measurement such as weight, height, or volume.
87) X chart is an example of a variables chart.
88) The first step in developing process control charts is to identify critical product
characteristics.
89) The central limit theorem states that when we plot the sample means, the sampling
distribution approximates a normal distribution.
90) The R chart is a process chart used to monitor the average of the characteristic being
measured.
91) The lower limit of R is zero for sample sizes less than or equal to six.
92) What are the steps used in developing process control charts?
93) Design a control chart to monitor the gas mileage in your car. Collect the data over time.
94) In a variables control chart, which of the following has likely occurred if two points in
succession are farther than two standard deviations from the mean?
A) erratic behavior
B) nonrandom event
C) process drift
D) natural variation
E) process run
95) In a variables control chart, which of the following has occurred if five points are in
succession, either all above or below the center line?
A) erratic behavior
B) nonrandom event
C) process drift
D) natural variation
E) process run
96) In a variables control chart, which of the following has occurred if seven points, either
increasing or decreasing, are in succession?
A) erratic behavior
B) nonrandom event
C) process drift
D) natural variation
E) process run
97) In a variables control chart, which of the following is likely to occur if large jumps of more
than three or four standard deviations take place?
A) erratic behavior
B) nonrandom event
C) process drift
D) natural variation
E) process run
98) In a variables control chart, five points in succession are called a process run.
99) In a variables control chart, large jumps of more than three or four standard deviations result
in process drift.
100) Provide two examples of process chart data point interpretations that are not necessarily
“out of control” but would still merit further investigation and have potential for corrective
actions.