Lean Six Sigma Yellow Belt Certification Measure Phase Tools 2 — Questions and Answers
Question 1: Which type of data is counted in discrete units and cannot be subdivided, such as the number of defective items?
- Continuous data
- Attribute data (Correct answer)
- Variable data
- Interval data
Correct answer: Attribute data
Attribute (discrete) data represents counts of events or defects and cannot take on fractional values.
Question 2: A process capability index of Cp = 1.33 indicates that a process is:
- Barely capable with high defect risk
- Capable with some margin (Correct answer)
- Highly capable with six-sigma performance
- Incapable and must be redesigned
Correct answer: Capable with some margin
Cp = 1.33 means the process spread fits within the specification limits with a reasonable safety margin, generally considered capable.
Question 3: In a measurement system analysis (MSA), 'reproducibility' refers to:
- Variation caused by different parts being measured
- Variation when the same operator measures the same part repeatedly
- Variation caused by different operators measuring the same part (Correct answer)
- Variation due to environmental conditions only
Correct answer: Variation caused by different operators measuring the same part
Reproducibility measures how consistently different operators obtain the same result when measuring the same part with the same gauge.
Question 4: What does the 'sigma level' of a process primarily describe?
- The standard deviation of the process mean
- How many standard deviations fit between the mean and the nearest specification limit (Correct answer)
- The total number of defects produced per month
- The average cycle time of the process
Correct answer: How many standard deviations fit between the mean and the nearest specification limit
Sigma level indicates how many standard deviations exist between the process mean and the closest specification limit, reflecting process performance.
Question 5: A run chart is most useful for:
- Identifying the root cause of a defect
- Detecting trends or shifts in process performance over time (Correct answer)
- Calculating the process capability index
- Comparing defect counts across multiple categories
Correct answer: Detecting trends or shifts in process performance over time
Run charts plot data in time sequence, making them ideal for spotting trends, cycles, or shifts before applying control charts.
Question 6: When constructing a histogram, the height of each bar represents:
- The cumulative percentage up to that interval
- The frequency or count of data points within that interval (Correct answer)
- The range of the data in that interval
- The median value of that interval
Correct answer: The frequency or count of data points within that interval
Each bar in a histogram shows how many data points fall within that class interval, revealing the data's distribution shape.
Question 7: Which measurement scale allows for meaningful ratios between values and has a true zero point?
- Nominal scale
- Ordinal scale
- Interval scale
- Ratio scale (Correct answer)
Correct answer: Ratio scale
Ratio scales have a true zero (absence of the quantity) and support all arithmetic operations including ratios, such as weight or length.
