Control: SPC & Control Charts
35 practice questions with explanations — 15 free to try
PassNova has 35 Lean Six Sigma Green Belt practice questions on Control: SPC & Control Charts, each with a clear explanation. A 15-question taster is free with no sign-up; the full bank is part of PassNova Premium. Updated for 2026.
Control: SPC & Control Charts: example questions & answers
3 worked examples with answers and explanations below. Try 15 Lean Six Sigma Green Belt questions free in the browser; the full 35-question Control: SPC & Control Charts bank is part of PassNova Premium.
Which control chart is most appropriate for monitoring individual measurements where the natural subgroup size is one?
- AIndividuals and Moving Range (I-MR) chart✓
- Bp-chart
- Cc-chart
- DX-bar and R chart
Answer: When data are collected as single observations rather than subgroups, the Individuals and Moving Range (I-MR) chart is the correct choice.
A team tracks the proportion of defective items in daily samples whose sizes vary from day to day. Which control chart should be used?
- AX-bar and S chart
- Bnp-chart
- Cc-chart
- Dp-chart✓
Answer: The p-chart monitors the proportion of defective units and accommodates varying subgroup sizes, unlike the np-chart which requires a constant sample size.
Which chart is designed to monitor the count of defects per inspection unit when the sample size (area of opportunity) is constant?
- Ap-chart
- BX-bar and R chart
- CI-MR chart
- Dc-chart✓
Answer: The c-chart tracks the number of defects (nonconformities) per unit when the area of opportunity is constant, modelled by the Poisson distribution.