Certified Six Sigma Black Belt Exam Practice 3

Question 1

A gauge R&R study reveals that measurement variation accounts for 35% of total observed variation. What is the appropriate action?

Accepted Answer

Improve or replace the measurement system before proceeding

Answer

A gauge R&R above 30% indicates an unacceptable measurement system that should be improved before drawing process conclusions.

Question 2

In the context of the transfer function Y = f(X), the Black Belt's primary goal during the Analyze phase is to:

Accepted Answer

Identify and validate the key X's driving Y

Answer

The Analyze phase identifies and confirms which input variables (X's) significantly influence the output (Y).

Question 3

A team uses a correlation coefficient of r = -0.92. This indicates:

Accepted Answer

A strong negative relationship

Answer

An r value close to -1 indicates a strong negative linear relationship between the two variables.

Question 4

Which statistical test is appropriate to determine if a process proportion defective has changed after an improvement?

Accepted Answer

1-proportion z-test

Answer

The 1-proportion z-test (or 2-proportion test) compares a sample proportion to a target or baseline proportion.

Question 5

A Black Belt wants to quantify how much a process output shifts for each unit change in a controlled input. Which analysis provides this directly?

Accepted Answer

Simple linear regression

Answer

Simple linear regression provides the slope coefficient, which quantifies the change in Y per unit change in X.

Certified Six Sigma Black Belt Exam Practice Test