Certified Six Sigma Black Belt Exam Certified Six Sigma Black Belt MCQ 3 — Questions and Answers
Question 1: A Black Belt calculates a p-value of 0.03 for a hypothesis test with α = 0.05. What is the correct conclusion?
- Fail to reject H0 because p > α/2
- Reject H0 because p < α (Correct answer)
- Accept H1 with 97% confidence
- The result is inconclusive
Correct answer: Reject H0 because p < α
Since p = 0.03 < α = 0.05, there is sufficient evidence to reject the null hypothesis.
Question 2: Which lean concept focuses on producing only what is needed, when it is needed, and in the amount needed?
- 5S
- Just-In-Time (JIT) (Correct answer)
- Poka-yoke
- Heijunka
Correct answer: Just-In-Time (JIT)
Just-In-Time is a core Toyota Production System principle that minimizes inventory by producing to demand.
Question 3: When performing a multiple regression analysis, the variance inflation factor (VIF) is used to detect:
- Heteroscedasticity
- Autocorrelation
- Multicollinearity (Correct answer)
- Non-normality of residuals
Correct answer: Multicollinearity
VIF measures how much the variance of a regression coefficient is inflated due to multicollinearity among predictors.
Question 4: In a reliability context, what does MTTF stand for and when is it used?
- Mean Time To Failure — for repairable systems
- Mean Time To Failure — for non-repairable systems (Correct answer)
- Maximum Time To Failure — for any system
- Mean Time To Fix — for repair operations
Correct answer: Mean Time To Failure — for non-repairable systems
MTTF (Mean Time To Failure) is the average time a non-repairable item operates before failing.
Question 5: A fishbone (Ishikawa) diagram is MOST useful during which DMAIC phase?
- Define
- Measure
- Analyze (Correct answer)
- Control
Correct answer: Analyze
The fishbone diagram is used in the Analyze phase to systematically identify potential root causes of a problem.
Question 6: Which Six Sigma metric represents the number of defect opportunities per unit?
- DPU
- DPMO
- DPO (Correct answer)
- Sigma level
Correct answer: DPO
DPO (Defects Per Opportunity) normalizes defect counts by the number of opportunities for defects per unit.
Question 7: What statistical distribution is used to model the time between failures in a constant-hazard (memoryless) reliability scenario?
- Weibull distribution
- Normal distribution
- Exponential distribution (Correct answer)
- Lognormal distribution
Correct answer: Exponential distribution
The exponential distribution models time between failures when the failure rate is constant, making it memoryless.
Certified Six Sigma Black Belt Exam Certified Six Sigma Black Belt MCQ 3
A Black Belt calculates a p-value of 0.03 for a hypothesis test with α = 0.05.
What is the correct conclusion?