Certified Six Sigma Black Belt Exam Hypothesis Testing 2

Question 1

A Six Sigma team sets α = 0.05. If the p-value from their test is 0.03, what is the correct conclusion?

Accepted Answer

Reject H₀ because p < α

Answer

When the p-value is less than the significance level α, you reject the null hypothesis.

Question 2

Which type of error occurs when you reject a true null hypothesis?

Accepted Answer

Type I error

Answer

A Type I error (false positive) is rejecting H₀ when it is actually true, and its probability equals α.

Question 3

A Black Belt wants to compare the means of three process lines simultaneously. Which test is most appropriate?

Accepted Answer

One-way ANOVA

Answer

One-way ANOVA is used to compare means across three or more groups simultaneously while controlling Type I error.

Question 4

Beta (β) in hypothesis testing represents which of the following?

Accepted Answer

Probability of a Type II error

Answer

Beta (β) is the probability of a Type II error — failing to reject a false null hypothesis.

Question 5

A process engineer tests whether a new supplier's material hardness (continuous, normal) differs from a target of 60 HRC. Which test should be used?

Accepted Answer

One-sample t-test

Answer

A one-sample t-test compares a sample mean to a known or specified target value.

Certified Six Sigma Black Belt Exam Practice Test