Lean Six Sigma Green Belt Certification Lean Six Sigma Green Belt Measure Phase and Statistics Questions and Answers 2 — Questions and Answers
Question 1: What is the primary purpose of a measurement system analysis (MSA) in the Measure phase?
- To evaluate the accuracy and precision of the measurement system (Correct answer)
- To identify root causes of defects
- To implement process improvements
- To validate customer requirements
Correct answer: To evaluate the accuracy and precision of the measurement system
MSA evaluates whether the measurement system produces reliable and consistent data before using it for process analysis.
Question 2: A process has a mean of 50 and a standard deviation of 5. What percentage of data falls within one standard deviation of the mean in a normal distribution?
- 68.26% (Correct answer)
- 95.44%
- 99.73%
- 50%
Correct answer: 68.26%
The empirical rule states that approximately 68.26% of data in a normal distribution falls within plus or minus one standard deviation of the mean.
Question 3: Which type of data would 'number of customer complaints per month' be classified as?
- Discrete data (Correct answer)
- Continuous data
- Attribute data
- Nominal data
Correct answer: Discrete data
Count data such as number of complaints is discrete because it can only take whole number values.
Question 4: What does a Gage R&R study specifically measure?
- Repeatability and reproducibility of a measurement system (Correct answer)
- Range and reliability of a process
- Risk and reward of a project
- Rate and ratio of defects
Correct answer: Repeatability and reproducibility of a measurement system
Gage R&R quantifies variation from the measurement device (repeatability) and variation from different operators (reproducibility).
Question 5: If a dataset has a positively skewed distribution, which relationship between the measures of central tendency is correct?
- Mean > Median > Mode (Correct answer)
- Mode > Median > Mean
- Mean = Median = Mode
- Median > Mean > Mode
Correct answer: Mean > Median > Mode
In a positively skewed distribution, the tail extends to the right, pulling the mean higher than the median, which is higher than the mode.
Question 6: What is the correct formula for calculating the coefficient of variation (CV)?
- (Standard deviation / Mean) × 100 (Correct answer)
- (Mean / Standard deviation) × 100
- (Range / Mean) × 100
- (Variance / Mean) × 100
Correct answer: (Standard deviation / Mean) × 100
The coefficient of variation expresses the standard deviation as a percentage of the mean, allowing comparison of variability across different scales.
Lean Six Sigma Green Belt Certification Lean Six Sigma Green Belt Measure Phase and Statistics Questions and Answers 2
What is the primary purpose of a measurement system analysis (MSA) in the Measure phase?