Basic Statistical Tools 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 Basic Statistical Tools flashcards as text
When constructing a histogram, the recommended number of bins for a dataset of 64 observations using the square-root rule is approximately:
Answer: 8
The square-root rule recommends √n bins; √64 = 8 bins.
In regression analysis, an R² value of 0.85 means:
Answer: 85% of the variation in Y is explained by the model
R² (coefficient of determination) represents the proportion of variation in the response variable explained by the predictor(s).
A process average is 100 units with σ = 4. The upper specification limit is 112. What is the Cpu?
Answer: 1.00
Cpu = (USL − mean) / 3σ = (112 − 100) / (3 × 4) = 12 / 12 = 1.00.
What is the primary purpose of a run chart in Six Sigma?
Answer: To monitor a process over time and detect trends or shifts
A run chart plots data in time sequence to reveal trends, cycles, or shifts in a process over time.
Which level of measurement allows calculation of ratios and has a true zero point?
Answer: Ratio
Ratio scale has a true zero point, making ratios meaningful (e.g., 20 kg is twice 10 kg).
In a normal probability plot, data that follow a straight line indicate:
Answer: The data are approximately normally distributed
If points on a normal probability plot fall approximately on a straight line, the data are consistent with a normal distribution.
A Lean Six Sigma team calculates a correlation coefficient (r) of −0.92 between machine temperature and defect rate. What can they conclude?
Answer: There is a strong negative linear relationship between temperature and defect rate
r = −0.92 indicates a strong negative linear association; correlation does not prove causation.