Certified Six Sigma Black Belt Exam FREE Certified Six Sigma Black Belt Hypothesis Testing Applications Questions and Answers 3

Question 1

A Six Sigma team needs to determine if there is a relationship between operator experience level (low, medium, high) and product pass/fail rate. Which test should they use?

Accepted Answer

Chi-square test of independence

Answer

A chi-square test of independence assesses whether two categorical variables are related.

Question 2

After a process change, a Black Belt collects yield data from two independent production lines to see if their mean yields differ. Which assumption is critical for a two-sample t-test?

Accepted Answer

Data should be approximately normally distributed

Answer

The two-sample t-test assumes that the underlying populations are approximately normally distributed, especially for small samples.

Question 3

A Black Belt sets alpha at 0.05 and beta at 0.10 for a hypothesis test. What does a beta of 0.10 represent?

Accepted Answer

10% chance of failing to reject a false null hypothesis

Answer

Beta is the probability of a Type II error, which is failing to reject the null hypothesis when it is actually false.

Question 4

Which hypothesis testing method is most appropriate for determining whether the median cycle time has changed when the data is highly skewed and non-normal?

Accepted Answer

Mann-Whitney U test

Answer

The Mann-Whitney U test is a nonparametric alternative that does not require normality and compares medians or distributions.

Question 5

A Black Belt performs a one-way ANOVA and obtains a significant result. What should be the next step to identify which specific groups differ?

Accepted Answer

Perform a post-hoc comparison test such as Tukey's HSD

Answer

A post-hoc test like Tukey's HSD identifies which specific group pairs have significantly different means after ANOVA.

Certified Six Sigma Black Belt Exam Practice Test

Certified Six Sigma Black Belt Exam Practice Test

Certified Six Sigma Black Belt Exam FREE Certified Six Sigma Black Belt Hypothesis Testing Applications Questions and Answers 3