ASQ Six Sigma Black Belt 4

Question 1

In a full factorial 2³ experiment with 3 factors at 2 levels each, how many experimental runs are required (without replication)?

Accepted Answer

8

Answer

A 2³ full factorial design requires 2³ = 8 experimental runs to test all combinations of 3 factors at 2 levels.

Question 2

Which FMEA severity rating criterion would typically be assigned to a failure mode that could cause injury without warning?

Accepted Answer

Rating 9-10 (very high/hazardous)

Answer

A severity rating of 9-10 is reserved for failure modes that involve safety hazards or regulatory non-compliance, especially those occurring without warning.

Question 3

What is the key distinction between 'common cause' and 'special cause' variation?

Accepted Answer

Common cause variation is random and systemic; special cause variation is assignable to a specific factor

Answer

Common cause (random) variation is inherent to the process and requires system-level changes to reduce, while special cause variation stems from identifiable, assignable factors.

Question 4

A Black Belt wants to test whether a process median has changed after an improvement. The data is non-normal and small-sample. Which test is most appropriate?

Accepted Answer

Wilcoxon signed-rank test

Answer

The Wilcoxon signed-rank test is the non-parametric equivalent of the one-sample t-test and is used when data is non-normal or the sample is small.

Question 5

In a multiple linear regression model, what does multicollinearity refer to?

Accepted Answer

High correlation among two or more predictor variables

Answer

Multicollinearity occurs when predictor variables are highly correlated with each other, inflating standard errors and making individual coefficient estimates unreliable.

ASQ - American Society for Quality Certification Practice Test

ASQ - American Society for Quality Certification Practice Test

ASQ Six Sigma Black Belt 4