Lean Six Sigma Green Belt Certification DMAIC: Analyze Phase Techniques 5

Question 1

A process improvement team wants to test whether the proportion of defective units differs between two production lines. Which test is most appropriate?

Accepted Answer

Two-proportion z-test

Answer

The two-proportion z-test compares proportions (attribute data) from two independent groups to determine if they are statistically different.

Question 2

When a team performs regression analysis and finds that adding a second X variable increases R² from 0.72 to 0.73, the BEST interpretation is:

Accepted Answer

The second variable adds minimal explanatory value and may not justify model complexity

Answer

A marginal R² increase suggests the second variable contributes little additional explanatory power while adding model complexity, so its inclusion should be questioned.

Question 3

In a Lean Six Sigma Analyze phase, what is the purpose of calculating takt time?

Accepted Answer

To set the pace of production required to meet customer demand

Answer

Takt time is calculated as available production time divided by customer demand, setting the required production pace to meet demand without overproduction.

Question 4

A team uses an affinity diagram during the Analyze phase. What is the PRIMARY output of this tool?

Accepted Answer

Ideas or data grouped into meaningful themes based on natural relationships

Answer

An affinity diagram organizes large amounts of qualitative data (ideas, observations) into related groups or themes through collaborative sorting.

Question 5

Which type of error occurs when a team concludes that a root cause IS significant when it actually has no real effect on the output?

Accepted Answer

Type I error (Alpha error)

Answer

A Type I error (false positive) occurs when the null hypothesis is incorrectly rejected, concluding a significant effect exists when it does not.

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification DMAIC: Analyze Phase Techniques 5