Measure Phase: Data Analysis Flashcards
7 cards from real Lean Six Sigma Black Belt Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Measure Phase: Data Analysis flashcards as text
A Black Belt uses Minitab to run a one-way ANOVA and obtains a p-value of 0.032. With alpha = 0.05, what is the correct conclusion?
Answer: Reject H0; at least one group mean differs significantly from the others
Since p = 0.032 < alpha = 0.05, we reject the null hypothesis and conclude that at least one group mean is significantly different.
What does the concept of 'rational subgrouping' mean in the context of control charts?
Answer: Grouping samples so that special causes appear between subgroups rather than within them
Rational subgrouping organizes data so within-subgroup variation reflects only common causes, maximizing the chance that special causes manifest as between-subgroup differences.
Which non-parametric test is the equivalent of the paired t-test when normality cannot be assumed?
Answer: Wilcoxon signed-rank test
The Wilcoxon signed-rank test is the non-parametric alternative to the paired t-test, comparing medians of two related samples when normality is violated.
In a scatter diagram, a correlation coefficient (r) of -0.92 indicates:
Answer: A strong negative linear relationship
A correlation coefficient of -0.92 indicates a strong negative linear relationship, meaning as one variable increases, the other decreases substantially.
A process engineer finds that the Pp is 1.6 but the Ppk is 0.9. What does this imply?
Answer: The process spread is adequate but the process is significantly off-center
A high Pp with a low Ppk indicates the process has sufficient inherent capability (spread) but is poorly centered relative to the specification limits.
Which data collection strategy best controls for the effect of time-related lurking variables?
Answer: Stratified random sampling by shift or time period
Stratified random sampling by shift or time period ensures representation across time-related strata, controlling for lurking temporal variables.
What is 'attribute agreement analysis' used to assess?
Answer: The consistency and accuracy of appraisers classifying categorical outcomes
Attribute agreement analysis evaluates how consistently appraisers agree with each other and with a known standard when making pass/fail or categorical judgments.