Lean Six Sigma Black Belt Practice Exam — All Questions
4 questions
Analyze
In hypothesis testing, if the p-value is 0.03 and alpha is 0.05, you should:
- a.Fail to reject the null hypothesis
- b.Reject the null hypothesis✓
- c.Increase the sample to 1,000 first
- d.Do nothing; p-values are irrelevant
Because p (0.03) < alpha (0.05), you reject the null hypothesis.
Analyze
A Type I error occurs when you:
- a.Reject a true null hypothesis (a false positive)✓
- b.Accept a true null hypothesis
- c.Increase the sample size
- d.Compute DPMO incorrectly
A Type I (alpha) error is rejecting a null hypothesis that is actually true.
Analyze
A correlation coefficient (r) of -0.9 indicates:
- a.No relationship
- b.A weak positive relationship
- c.A strong negative linear relationship✓
- d.A guaranteed causal link
r = -0.9 indicates a strong negative linear correlation (correlation is not causation).
Analyze
Which tool helps prioritize the 'vital few' causes contributing most to a problem?
- a.Control chart
- b.Gage R&R
- c.SIPOC
- d.Pareto chart✓
A Pareto chart highlights the vital few causes (the 80/20 principle).