Six Sigma Black Belt
Practice Exam Questions
1. A thorough review of the works of the major quality gurus would indicate which
of the following to be the most effective way to create quality
a. Effective problem solving
b. Benchmarking the best competitive practices
c. Continuous process improvement
d. Modern statistical control methods
2. Consider the following quality concepts and then identify the appropriate quality
management luminary that is not identified with any of them. (I) Company wide
quality control, (II) Six Sigma; (III) Quality trilogy; (IV) Signal to Noise Ratio,
(V) Zero defects, (VI) The quality explosion, (VII) Total quality control
a. Armand Feigenbaum
b. W. Edwards Deming
c. Kaoru Ishikawa
d. Stephen Covey
e. Mikel Harry
3. Which one of the following usually represents the greatest problem in quality
team operations
a. Facilitator/leader conflicts
b. Lack of ideas of team members
c. Interruptions in meetings
d. Lack of time by team members
4. The advantages of a quality cost system would not include which of the following
items
a. Aligns quality and company goals
b. Provides a prioritization system for the allocation of resources
c. Insures the resolution of specific quality problems
d. Provides a manageable overview of quality
5. If prevention costs are increased to pay for engineering work in quality and this
results in a reduction in the number of product defects, this yields a reduction in
a. Appraisal costs
b. Operating costs
c. Quality costs
d. Failure costs
6. For six sigma success, what structure sequence should be followed regarding the
following: (I) develop a policy, (II) establish a steering committee, (III) establish
strategic goals, (IV) train on statistical methods
a. II, III, IV, I
b. II, I, III, IV
c. III, II, I, IV
d. I, II, III, IV
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Six Sigma Black Belt
Practice Exam Questions
7. The greatest contribution of a reliability effort is made in the
a. Design
b. Manufacturing
c. Shipping
d. Field service
8. An operation requires shipments from your vendor of very small lots of fixed size.
The attribute sampling plan used for receiving inspection should have its OC
curve developed using which distribution
a. Binomial
b. Normal
c. Poisson
d. Hypergeometric
9. Two quantities which uniquely determine a single sampling attributes plan are
a. AQL and LTPD
b. Sample size and acceptance number
c. AQL and producer’s risk
d. LTPD and consumer’s risk
10. Under acceptance sampling, with screening, average outgoing quality will not be
worse, in the long run, than the
a. ATI
b. AQL
c. AOQL
d. AOQ
11. Considerations to be made prior to the use of any sampling plan include (I)
consumer and producer risks must be specified, (II) method of selecting samples
must be specified, (III) characteristics to be inspected must be specified
a. I only
b. I and II only
c. I and III only
d. I, II, and III
12. The steeper the OC curve, the
a. Less protection for both producer and consumer
b. More protection for consumer and less for producer
c. The lower the AQL
d. The smaller the sample size
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Six Sigma Black Belt
Practice Exam Questions
13. In the failure rate model shown below, the part of the curve identified as “A”
represents
B
A
C
a. The bath tub curve
b. Random Poisson failures
c. The burn in failure period
d. Wear out failure
14. If two components having equal reliabilities of .92 were added in parallel with a
component of .6585 reliability in series what would the resultant system reliability
be?
a. .9941
b. .6543
c. .6818
d. .7121
15. If the mean time between failures has been found to be 13 hours for a given
component, what is the reliability at t = 13.2 hours?
a. .920
b. .206
c. .362
d. .985
16. Two disadvantages of a fishbone diagram are (I) it displays causes in a nongraphical manner, (II) it takes time to perform and prioritize, (III) It presents the
problem graphically, (IV) It does not develop an action plan
a. I and III only
b. I and II only
c. II and IV only
d. I and IV only
17. What other problem solving tool is customarily used to complement the fishbone
diagram?
a. Scatter diagram
b. Pareto diagram
c. Brainstorming
d. FFA
18. Scatter diagrams are useful in problem solving because they
a. Display the significant few
b. Eliminate the trivial many
c. Show relationships between variables
d. Highlight special causes
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Six Sigma Black Belt
Practice Exam Questions
19. Basic information about data, such as central location, width, spread, and shape
can be visualized using which tool
a. p chart
b. Affinity diagram
c. Relationship diagram
d. Histogram
20. If the probability of a car starting on a cold morning is .6 and we have two such
cars, what is the probability of at least one of the cars starting on a cold morning?
a. .84
b. .81
c. .60
d. .36
21. For the normal probability distribution, the relationships among the median,
mean, and mode are that
a. They are all equal to the same value
b. The mean and mode have the same value but the median is different
c. Each has a value different from the other two
d. The mean and the median are the same but the mode is different
μ x e -μ
22. The expression P(x) 
refers to the
x!
a. Poisson distribution
b. Pascal distribution
c. Beta distribution
d. Binomial distribution
23. The average number of flaws in large plate glass is .25 per pane. The standard
deviation of this Poisson distribution is
a. .25
b. .05
c. .75
d. .50
24. You have been asked to sample a lot of 300 units from a vendor whose past
quality has been about 2% defective. A sample of 40 pieces is drawn from the lot
and you have been told to reject the lot if you find two or more parts defective.
What is the probability of finding two or more parts defective?
a. .953
b. .809
c. .191
d. .047
25. A process which is in statistical control will (I) produce product to specifications,
(II) consistently produce product which, when charted, will fall within statistical
control limits, (III) results in a Cpk value of 1.0 or better.
a. I only
b. II only
c. II and III only
d. I, II, and III
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Six Sigma Black Belt
Practice Exam Questions
26. An xbar and R chart was prepared for an operation using 20 samples with 5 pieces
in each sample. x was found to be 33.6 and R was 6.2. During production a
sample of 5 was taken and the pieces measured 36, 43, 37, 25, and 38. 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
27. A process is checked by inspection of random samples of four shafts after a
polishing operation and xbar and R charts are maintained. A person making a spot
check picks out two shafts, measures them accurately, and plots the value of each
on the xbar chart. Both points fall just outside the control limits. He advises the
department supervisor to stop the process. This decision indicates that
a. The average is out of control
b. Both the average and range charts are out of control
c. The range is out of control
d. The person is not using the chart correctly
28. In a normal distribution what is the area under the curve between +.7 and +1.3
standard deviation units?
a. .2903
b. .7580
c. .2580
d. .1452
29. Given x  51.0 and R  4.0 with n  5 and assuming statistical control, what
proportion of the population will meet specs of 50 + 3?
a. .87
b. .81
c. .91
d. .93
30. The process has been performing satisfactorily for some time. An improvement is
required. Your response is to
a. Direct the workforce to be more careful in their work
b. Issue a slogan “DMAIIC”
c. Identify the special causes to correct the process
d. Identify the common causes to correct the process
31. The results of a designed experiment are to be analyzed using a chi square test.
There are five treatments under consideration and each treatment falls under two
categories (success or failure). The calculated value of chi-square is compared to
the tabulated value with how many degrees of freedom?
a. 10
b. 9
c. 5
d. 4
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Six Sigma Black Belt
Practice Exam Questions
32. Ratios of two variances drawn from the same normal population are described by
which of the following distributions?
a. F
b. Student t
c. Chi-square
d. Normal
33. If the 95% confidence limits for the  turns out to be 6.5 and 8.5 it means
a. The probability is .95 that x falls between 6.5 and 8.5
b. The probability is that x falls between 6.5 and 8.5
c. The probability is .95 that the interval contains .
d. 4 =8.5-6.5
34. Determine whether the following two samples have significantly different
variances at the 5% level:
Sample A has  2  1347 based on a sample size of 61 and sample B has  2
of 2237 based on a sample of 31.
a. Significant difference because Ftest<Ftable
b. No significant difference because Ftest< Ftable
c. Significant difference because Ftest > Ftable
d. No significant difference because Ftest > Ftable
35. When finding a confidence interval for mean  based on a sample size of n
a. Increasing n increases the interval
b. Having to use Sx instead of n decreases the interval
c. The larger the interval the better the estimate of 
d. Increasing n decreases the interval
36. If a sample size of 16 yields an average of 12 and a standard deviation of 3,
estimate the 95% CI for the mean
a. 10.4, 13.6
b. 10.45, 13.55
c. 10.53, 13.47
d. 10.77, 13.23
37. An experiment with two factors, in which all levels of one variable are run at each
level of the second variable is called a
a. One way experiment
b. Latin square experiment
c. Factorial experiment
d. Fractional factorial experiment
38. A 32 experiment means that we are considering
a. Two levels of three factors
b. Two dependent variables and three independent variables
c. Two go/no go variables and three continuous variables
d. Three levels of two factors
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Six Sigma Black Belt
Practice Exam Questions
39. When constructing a factorial experiment which of the following is true
a. Factorial experiments may not contain any number of levels per factor.
They must be the same for each factor
b. Confounding takes place in factorials when we run a fractional part of the
complete experiment
c. Contrasts and treatment combinations are the same
d. In factorials, the factors must be quantitative
40. A two way ANOVA has r levels for one variable and c levels for a second with 2
observations per cell. The degree of freedom for interaction is
a. 2rc
b. (r-1)(c-1)
c. rc-1
d. 2(r-1)(c-1)
41. Consider the SS and MS columns of an ANOVA table for a single factor design.
The appropriate ratio for testing the null hypothesis of no treatment effect is
a. SS treatments divided by SS residual
b. MS treatments divided by MS residual
c. SS treatments divided by MS residual
d. MS treatments divided by SS residual
42. A study was conducted on the relationship between the speed of different cars and
their mileage. The correlation coefficient was found to be .35. Later it was
discovered that there was a defect in the speedometers and they had all been set 5
miles per hour too fast. The correlation coefficient was computed using the
corrected scores. Its new value will be
a. .30
b. .35
c. .40
d. -.35
43. The objective of six sigma is to
a. Increase variability
b. Reduce variability
c. Decrease customer satisfaction
d. Hit the customer’s target
e. Both b and d above
44. Which of the following is not part of Deming’s Theory of profound knowledge?
a. Knowledge of processes
b. Knowledge of statistics and variation
c. Knowledge of psychology or motivation
d. Knowledge of general systems theory
45. Champions are expected to do all of the following except
a. Lead teams
b. Provide support
c. Provide resources
d. Remove barriers
e. Prevent scope creep
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Six Sigma Black Belt
Practice Exam Questions
Answers
Question
Answer
Question
Answer
1
2
3
4
5
6
7
c
d
a
c
d
b
a
24
25
26
27
28
29
30
c
b
d
d
d
a
d
8
9
10
11
12
13
14
15
16
c
b
c
d
b
c
b
c
c
31
32
33
34
35
36
37
38
39
d
a
c
c
d
a
c
d
b
17
18
19
20
21
22
23
c
c
d
a
a
a
d
40
41
42
43
44
45
b
b
b
e
d
a
8