Lean Six Sigma Black Belt Certification Lean Six Sigma Black Belt Analyze Phase: Hypothesis Testing Questions and Answers 2

Question 1

In a two-sample t-test comparing process means, what does a p-value of 0.03 indicate at a significance level of 0.05?

Accepted Answer

Reject the null hypothesis; the means are statistically different

Answer

A p-value of 0.03 is less than the significance level of 0.05, so we reject the null hypothesis and conclude the means differ significantly.

Question 2

Which hypothesis test is most appropriate for comparing the variance of a single sample against a known population variance?

Accepted Answer

Chi-square test

Answer

The chi-square test is used to compare a single sample variance to a specified population variance.

Question 3

What is a Type II error in the context of hypothesis testing?

Accepted Answer

Failing to reject a false null hypothesis

Answer

A Type II error occurs when we fail to reject the null hypothesis even though it is actually false.

Question 4

When conducting an ANOVA test across four process groups, what does a statistically significant F-statistic tell you?

Accepted Answer

At least one group mean differs from the others

Answer

A significant F-statistic in ANOVA indicates that at least one group mean is significantly different, but not which specific ones differ.

Question 5

What is the primary purpose of a paired t-test in the Analyze phase?

Accepted Answer

To compare means of two related measurements from the same subjects

Answer

A paired t-test compares two related measurements taken from the same subjects, such as before-and-after a process change.

Lean Six Sigma Black Belt Certification Practice Test