Certified Six Sigma Black Belt Exam Certified Six Sigma Black Belt MCQ 5

Question 1

What does a Weibull shape parameter (β) less than 1 indicate about a product's failure pattern?

Accepted Answer

Infant mortality — decreasing failure rate over time

Answer

β < 1 in the Weibull distribution indicates decreasing failure rate, characteristic of early-life or infant mortality failures.

Question 2

Which mistake-proofing (poka-yoke) method prevents an error from being passed to the next operation?

Accepted Answer

Control method

Answer

The control method physically prevents the defect from moving forward, while warning methods only alert the operator.

Question 3

In ANOVA, the F-statistic is calculated as:

Accepted Answer

Between-group variance / Within-group variance

Answer

The F-statistic is the ratio of between-group (treatment) mean square to within-group (error) mean square.

Question 4

When calculating process sigma level, a 1.5 sigma shift is typically applied because:

Accepted Answer

Long-term processes drift up to 1.5σ from their short-term mean

Answer

Motorola's empirical finding is that processes shift up to ±1.5σ over time due to factors like tool wear and material variation.

Question 5

A Black Belt is conducting a DOE and wants to estimate the effect of a two-factor interaction. What is the minimum number of runs required?

Accepted Answer

4

Answer

A 2^2 full factorial (4 runs) is the minimum to estimate main effects and a two-factor interaction with two factors.

Certified Six Sigma Black Belt Exam Practice Test