Certified Six Sigma Black Belt Exam Certified Six Sigma Black Belt Practice 1

Question 1

A Black Belt wants to assess the relationship between a continuous input variable and a continuous output variable. Which statistical method is most appropriate for quantifying this relationship?

Accepted Answer

Simple linear regression

Answer

Chi-square test of independence

Answer

One-sample t-test

Answer

ANOVA

Question 2

In the Control phase, a process shows a sudden shift in the mean on an X-bar chart. Which out-of-control rule most directly detects this type of shift?

Accepted Answer

One point beyond the 3-sigma control limit

Answer

Eight consecutive points on one side of the centerline

Answer

Two out of three points beyond the 2-sigma warning limit

Answer

Fifteen consecutive points within the 1-sigma zone

Question 3

A Six Sigma team calculates a process Cp of 1.5 but a Cpk of 0.8. What does this discrepancy most likely indicate?

Accepted Answer

The process is significantly off-center relative to the specification limits

Answer

The measurement system is inadequate

Answer

The process spread is too wide relative to specification limits

Answer

The sample size used was insufficient

Question 4

During the Improve phase, a team runs a 2^3 full factorial experiment and discovers a significant two-factor interaction between factors A and B. What is the best next step?

Accepted Answer

Set factor A at the level that makes the B effect most favorable, then optimize B

Answer

Ignore the interaction and optimize each factor independently

Answer

Discard factor B and re-run the experiment

Answer

Convert the design to a Taguchi L8 array

Question 5

A Black Belt is selecting a sampling plan to verify incoming material quality. The team wants to control the risk of accepting a bad lot (consumer's risk) at no more than 10%. Which parameter directly defines this risk?

Accepted Answer

Beta (β)

Answer

Alpha (α)

Answer

Acceptable Quality Level (AQL)

Answer

Lot Tolerance Percent Defective (LTPD)

Question 6

Which of the following best describes the purpose of a transfer function (Y = f(X)) in a Six Sigma project?

Accepted Answer

To mathematically model the relationship between process inputs and the critical output

Answer

To document the handoff of project deliverables to the process owner

Answer

To calculate the financial benefit of the project for the business case

Answer

To map the flow of materials and information across the value stream