Certified Six Sigma Black Belt Exam General 4

Question 1

A Black Belt applies the 5 Whys technique during a problem-solving session. What is its primary limitation?

Accepted Answer

It relies on team knowledge and can lead to different root causes depending on participants

Answer

The 5 Whys is subjective and team-dependent, meaning different groups analyzing the same problem may arrive at different root causes.

Question 2

In the context of Statistical Process Control, what does the Western Electric Rule 2 (also called the '2-of-3 rule') detect?

Accepted Answer

Two of three consecutive points beyond 2 sigma on the same side of the centerline

Answer

Western Electric Rule 2 flags a potential shift when 2 of 3 consecutive points fall beyond the 2-sigma warning limit on the same side of the center line.

Question 3

Which of the following best describes the purpose of a SIPOC diagram in the Define phase?

Accepted Answer

To provide a high-level view of the process and identify key stakeholders and boundaries

Answer

A SIPOC diagram gives project teams a macro-level view of the process, capturing Suppliers, Inputs, Process steps, Outputs, and Customers to establish scope.

Question 4

What does 'confounding' mean in the context of a fractional factorial experiment?

Accepted Answer

Two or more effects cannot be estimated independently because they are aliased with each other

Answer

Confounding (aliasing) occurs when the design cannot distinguish between two effects because they are mathematically identical in the chosen fraction of the experiment.

Question 5

A Black Belt calculates a p-value of 0.02 for a hypothesis test with α = 0.05. What is the correct conclusion?

Accepted Answer

Reject H₀; the result is statistically significant

Answer

Since p (0.02) < α (0.05), there is sufficient evidence to reject the null hypothesis; the result is statistically significant at the chosen significance level.

Certified Six Sigma Black Belt Exam Practice Test

Certified Six Sigma Black Belt Exam Practice Test

Certified Six Sigma Black Belt Exam General 4