Hypothesis Testing Flashcards
7 cards from real Certified Six Sigma Black Belt Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Hypothesis Testing flashcards as text
Which condition must be met to validly use a two-sample t-test with pooled variance?
Answer: Population variances must be assumed equal
The pooled two-sample t-test assumes the two populations have equal variances; use Welch's t-test when this assumption fails.
A team detects a statistically significant difference in cycle times but the improvement is only 0.5 seconds on a 10-minute process. Which concept explains why this finding may not matter?
Answer: Practical significance / effect size
Practical significance considers whether the detected effect is large enough to be meaningful in context, independent of statistical significance.
The Kruskal-Wallis test is the non-parametric equivalent of which parametric test?
Answer: One-way ANOVA
Kruskal-Wallis tests for differences in median ranks across three or more independent groups, analogous to one-way ANOVA.
A Black Belt runs a hypothesis test and obtains p = 0.12 with α = 0.05. The correct conclusion is:
Answer: Fail to reject H₀; insufficient evidence to conclude a difference
Failing to reject H₀ means there is insufficient evidence to support H₁; it does not prove H₀ is true.
In a two-tailed hypothesis test with α = 0.05, the critical region is located:
Answer: Split equally (2.5%) in each tail
A two-tailed test divides α equally between both tails, placing 2.5% in each tail for α = 0.05.
Which of the following BEST describes the purpose of a paired t-test?
Answer: Comparing means of matched or before/after measurements
The paired t-test accounts for within-subject or matched-pair correlation, reducing variability and increasing test sensitivity.
A process engineer finds the Anderson-Darling p-value is 0.021 for a dataset. What does this indicate?
Answer: The data significantly deviates from a normal distribution
A low p-value in the Anderson-Darling test (below α) leads to rejecting the null hypothesis of normality.