Lean Six Sigma Black Belt Certification FREE Lean Six Sigma Black Belt Analyze Phase: Hypothesis Testing Questions and Answers 2 — Questions and Answers
Question 1: In hypothesis testing, what does a Type II error represent?
- Rejecting a true null hypothesis
- Failing to reject a false null hypothesis (Correct answer)
- Accepting the alternative hypothesis correctly
- Rejecting the alternative hypothesis correctly
Correct answer: Failing to reject a false null hypothesis
A Type II error (beta error) occurs when the test fails to reject the null hypothesis even though it is actually false.
Question 2: Which hypothesis test is most appropriate for comparing the means of three or more groups simultaneously?
- Two-sample t-test
- Paired t-test
- One-way ANOVA (Correct answer)
- Chi-square test
Correct answer: One-way ANOVA
One-way ANOVA is designed to compare means across three or more groups to determine if at least one differs significantly.
Question 3: What is the relationship between confidence level and significance level (alpha) in hypothesis testing?
- Confidence level equals alpha
- Confidence level equals 1 minus alpha (Correct answer)
- Confidence level equals alpha squared
- Confidence level equals 2 times alpha
Correct answer: Confidence level equals 1 minus alpha
The confidence level is calculated as 1 minus alpha, so a 0.05 significance level corresponds to a 95% confidence level.
Question 4: When conducting a hypothesis test, what does increasing the sample size primarily affect?
- The significance level
- The confidence interval width only
- The power of the test (Correct answer)
- The Type I error rate
Correct answer: The power of the test
Increasing sample size increases statistical power, making it more likely to detect a true effect when one exists.
Question 5: In a Lean Six Sigma project, a Black Belt uses a two-proportion test. What type of data is being analyzed?
- Continuous data from two populations
- Attribute data from two populations (Correct answer)
- Time series data from one population
- Ordinal data from three populations
Correct answer: Attribute data from two populations
A two-proportion test compares the proportion of occurrences (attribute/discrete data) between two groups.
Question 6: What assumption must be verified before using a two-sample t-test to compare process means?
- Data must be categorical
- Samples must be dependent
- Data should be approximately normally distributed (Correct answer)
- Sample sizes must be exactly equal
Correct answer: Data should be approximately normally distributed
The two-sample t-test assumes the data in each group is approximately normally distributed, which should be verified before conducting the test.
Lean Six Sigma Black Belt Certification FREE Lean Six Sigma Black Belt Analyze Phase: Hypothesis Testing Questions and Answers 2
In hypothesis testing, what does a Type II error represent?