Certified Six Sigma Black Belt Exam FREE Certified Six Sigma Black Belt Questions and Answers 2 — Questions and Answers
Question 1: Which statistical test is most appropriate for comparing the means of three or more groups in a Six Sigma project?
- Chi-square test
- One-way ANOVA (Correct answer)
- Paired t-test
- Mann-Whitney U test
Correct answer: One-way ANOVA
One-way ANOVA is used to determine whether there are statistically significant differences between the means of three or more independent groups.
Question 2: In a Six Sigma DMAIC project, what is the primary purpose of the Control phase?
- Identify root causes of defects
- Establish monitoring systems to sustain improvements (Correct answer)
- Select the best improvement solution
- Define customer requirements
Correct answer: Establish monitoring systems to sustain improvements
The Control phase focuses on implementing control plans and monitoring systems to ensure that improvements are maintained over time.
Question 3: A process has a Cp of 1.5 and a Cpk of 0.8. What does this indicate?
- The process is both capable and centered
- The process is capable but not centered within specification limits (Correct answer)
- The process is neither capable nor centered
- The process spread exceeds the specification width
Correct answer: The process is capable but not centered within specification limits
A Cp of 1.5 shows adequate spread relative to specifications, but the lower Cpk of 0.8 indicates the process mean has shifted away from center.
Question 4: What is the primary risk of using a high alpha level (e.g., 0.10) in hypothesis testing during a Six Sigma project?
- Increased probability of a Type II error
- Decreased statistical power
- Increased probability of a Type I error (Correct answer)
- Reduced sample size requirements
Correct answer: Increased probability of a Type I error
A higher alpha level increases the probability of rejecting the null hypothesis when it is actually true, which is a Type I error.
Question 5: Which tool is used to prioritize potential failure modes based on severity, occurrence, and detection ratings?
- Pareto chart
- Failure Mode and Effects Analysis (Correct answer)
- Control chart
- Fishbone diagram
Correct answer: Failure Mode and Effects Analysis
FMEA systematically evaluates potential failures by assigning severity, occurrence, and detection scores to calculate a Risk Priority Number.
Question 6: In Design of Experiments, what is the main advantage of a fractional factorial design over a full factorial design?
- It eliminates all confounding effects
- It requires fewer experimental runs while still estimating main effects (Correct answer)
- It provides higher statistical power
- It allows testing of more factor levels
Correct answer: It requires fewer experimental runs while still estimating main effects
Fractional factorial designs reduce the number of runs needed by strategically confounding higher-order interactions that are often negligible.
Certified Six Sigma Black Belt Exam FREE Certified Six Sigma Black Belt Questions and Answers 2
Which statistical test is most appropriate for comparing the means of three or more groups in a Six Sigma project?