Six Sigma Green Belt Practice Test

Six Sigma Green Belt Measure Phase Practice Questions

Measure Phase makes up 10 of every 50 questions on a Tigertest Six Sigma Green Belt practice test. Here are 10 of the 40 questions on it, each with the answer and the reason.

Updated 2026-11-10 by the Tigertest team. Based on the ASQ CSSGB Body of Knowledge (2022). Original questions; 50 per test, weighted like the real exam, with a 70% readiness line. Not affiliated with ASQ.

1. 1. A team maps a process as it actually runs and compares it with the written work instruction. What is it looking for?

   • A.The best supplier to use
   • B.Gaps from the written procedure
   • C.The process's current sigma level
   • D.The cost of each process step

   Answer: B. Walking the real process and comparing it with documents reveals steps that are skipped, added or done differently, which often explain variation.

2. 2. On a standard flowchart, what does a diamond symbol represent?

   • A.The start or end
   • B.A document
   • C.A process step
   • D.A decision point

   Answer: D. Diamonds mark yes/no or branching decisions. Rectangles are process steps and rounded ovals are start and end points.

3. 3. Two independent machines have failure probabilities of 0.08 and 0.05 on a given day. What is the chance both fail that day?

   • A.0.004
   • B.0.04
   • C.0.13
   • D.0.126

   Answer: A. For independent events, P(A and B) = P(A) x P(B) = 0.08 x 0.05 = 0.004. Adding them gives 0.13, which is not a probability of both.

4. 4. Using the same machines (0.08 and 0.05, independent), what is the chance at least one fails?

   • A.0.004
   • B.0.874
   • C.0.126
   • D.0.13

   Answer: C. P(A or B) = P(A) + P(B) - P(A and B) = 0.08 + 0.05 - 0.004 = 0.126. Leaving out the overlap gives 0.13.

5. 5. A part is red with probability 0.30 and blue with probability 0.25, and no part is both. What is P(red or blue)?

   • A.0.475
   • B.0.45
   • C.0.55
   • D.0.075

   Answer: C. Mutually exclusive events cannot happen together, so P(red or blue) = 0.30 + 0.25 = 0.55 with nothing to subtract.

6. 6. How many different teams of 3 can be chosen from 9 operators if order does not matter?

   • A.84
   • B.27
   • C.729
   • D.504

   Answer: A. Combinations: 9! / (3! x 6!) = 84. Counting ordered choices gives 9 x 8 x 7 = 504, which is the permutation.

7. 7. Seven parts go into 3 numbered slots, one per slot. How many ordered arrangements are possible?

   • A.343
   • B.35
   • C.21
   • D.210

   Answer: D. Order matters, so this is a permutation: 7 x 6 x 5 = 210. The combination 7C3 = 35 ignores order.

8. 8. What does the central limit theorem say about sample means?

   • A.They vary more as n grows
   • B.They become close to normal
   • C.They equal the population mean
   • D.They follow the population's shape

   Answer: B. Whatever the population's shape, the distribution of sample means approaches normal as sample size grows, with standard error sigma divided by the square root of n.

9. 9. A population has standard deviation 12. What is the standard error of the mean for samples of 36?

   • A.12
   • B.2
   • C.0.33
   • D.6

   Answer: B. Standard error = sigma / square root of n = 12 / 6 = 2. Dividing by n instead of its square root gives 0.33.

10. 10. Which distribution models the number of defective units in a fixed sample of 50?

    • A.Normal
    • B.Chi square
    • C.Poisson
    • D.Binomial

    Answer: D. A fixed number of trials, each defective or not with the same probability, gives a binomial count. Poisson models defects per unit of area, time or product.