Measure Phase and Statistics Flashcards
7 cards from real Lean Six Sigma Green Belt Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Measure Phase and Statistics flashcards as text
A process has a mean of 50 and a standard deviation of 5. What is the coefficient of variation (CV)?
Answer: 10%
CV = (standard deviation / mean) × 100 = (5/50) × 100 = 10%.
Which measurement scale allows calculation of meaningful ratios between values?
Answer: Ratio
Ratio scales have a true zero point, allowing meaningful ratio comparisons such as 'twice as much.'
In a Gage R&R study, if reproducibility is very high relative to total variation, what is the most likely cause?
Answer: Different operators measure the same part differently
High reproducibility variation indicates operator-to-operator differences are contributing significantly to measurement variation.
A control chart shows a run of 8 consecutive points on one side of the centerline. This is an example of:
Answer: A special cause signal
Eight or more consecutive points on the same side of the centerline is a standard Western Electric rule indicating a non-random special cause.
What does kurtosis measure in a data distribution?
Answer: The peakedness and tail heaviness of the distribution
Kurtosis measures how peaked or flat a distribution is relative to a normal distribution, and the weight of its tails.
Which sampling method divides a population into subgroups and randomly samples from each subgroup proportionally?
Answer: Stratified sampling
Stratified sampling ensures representation from all key subgroups by sampling proportionally from each stratum.
A process produces 25 defective units out of 500 total units. What is the defect rate in parts per million (PPM)?
Answer: 50,000
PPM = (defects / total units) × 1,000,000 = (25/500) × 1,000,000 = 50,000 PPM.