ASQ ASQ Certified Quality Engineer (CQE) 1 — Questions and Answers
Question 1: In statistical process control (SPC), what does 'common cause variation' refer to?
- Variation due to special assignable causes
- Inherent, natural variation in a process (Correct answer)
- Variation caused by equipment malfunction
- Variation due to operator error
Correct answer: Inherent, natural variation in a process
Common cause variation is the natural, inherent variability in a stable process resulting from the system itself, not from specific identifiable causes.
Question 2: Which control chart is used to monitor the proportion of defective items in a sample?
- X-bar chart
- R chart
- p chart (Correct answer)
- c chart
Correct answer: p chart
The p chart monitors the proportion (fraction) of defective items in samples of varying or equal size, making it an attribute chart.
Question 3: What is the primary purpose of a Pareto chart in quality management?
- To show the relationship between two variables
- To display process variation over time
- To identify and prioritize the most significant causes of problems (Correct answer)
- To compare a distribution to a normal curve
Correct answer: To identify and prioritize the most significant causes of problems
A Pareto chart arranges categories by frequency or impact to identify the 'vital few' causes responsible for most problems, applying the 80/20 rule.
Question 4: In a normal distribution, approximately what percentage of data falls within ±2 standard deviations of the mean?
- 68.3%
- 95.4% (Correct answer)
- 99.7%
- 90.0%
Correct answer: 95.4%
Approximately 95.4% of data in a normal distribution falls within ±2 standard deviations of the mean, per the empirical (68-95-99.7) rule.
Question 5: What does the process capability index Cpk measure?
- The ratio of process spread to specification spread only
- How well a process meets specifications considering both spread and centering (Correct answer)
- The number of defects per million opportunities
- The variation between subgroup averages
Correct answer: How well a process meets specifications considering both spread and centering
Cpk measures process capability by considering both the process spread relative to specifications and how centered the process mean is within the specification limits.
Question 6: Which sampling plan standard is most commonly referenced for attribute acceptance sampling in the U.S.?
- MIL-STD-1916
- ANSI/ASQ Z1.4 (Correct answer)
- ISO 9001
- ASTM E11
Correct answer: ANSI/ASQ Z1.4
ANSI/ASQ Z1.4 is the standard acceptance sampling plan for attributes, defining procedures and AQL-based tables for lot-by-lot inspection.
Question 7: What is the null hypothesis (H₀) in statistical hypothesis testing?
- The hypothesis that states there is a significant difference
- The alternative hypothesis being evaluated
- The hypothesis that assumes no difference or effect exists (Correct answer)
- The hypothesis with the highest probability of being true
Correct answer: The hypothesis that assumes no difference or effect exists
The null hypothesis (H₀) assumes no difference, relationship, or effect exists between variables and serves as the default baseline assumption to be tested.
ASQ ASQ Certified Quality Engineer (CQE) 1
In statistical process control (SPC), what does 'common cause variation' refer to?