Quality Control (SPC) for an exam-score curve
Simulate an exam-score curve live in your browser. This runs the real Quality Control (SPC) solver — adjust the inputs, watch it respond instantly, and export the result. No install, no account.
Controls
Presets
Statistical process control watches a process over time against control limits set at three standard deviations from the target. Points inside are normal random variation — leave them alone. A point beyond the limits, or a run trending one way, signals a real change worth investigating. Nudge the process shift and watch points breach the limits.
Data Inspector
Governing equation
Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.
Controls
Presets
Cp compares the spec width to the process spread — can the process fit inside the tolerances at all? Cpk also accounts for how well-centered it is. A Cpk of 1.33 is the usual bar for capable; 2.0 is Six Sigma quality with just 3.4 defects per million. Widen the spread or push the mean off-center and defects climb fast.
Data Inspector
Capability indices
Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.
Controls
Presets
A hypothesis test asks whether a sample mean is far enough from the null value to be surprising by chance alone. The test statistic z measures that distance in standard errors; if it falls in the red rejection region (p below 0.05) we reject the null. Larger samples shrink the standard error and sharpen the test.
Data Inspector
Governing equation
Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.
About this simulation
The full Quality Control (SPC) tool models an exam-score curve with the same numerics engineers and scientists use — running entirely client-side. Change any parameter and the result updates in real time, so you can build intuition, check a design, or teach the concept without spreadsheets or installs.
More you can do with Quality Control (SPC)
Other ways to simulate an exam-score curve
Frequently asked questions
- How do I simulate an exam-score curve?
- Open this page and use the live Quality Control (SPC) tool below — set your inputs and the simulation runs instantly in your browser using real numerics. No install, no account needed.
- Is it free?
- Yes. The simulation runs free in your browser. A one-time unlock or a Pro plan adds advanced parameters, saved presets, data import, and clean exports.
- Can I use my own numbers?
- Absolutely — every input is adjustable, and with data import you can drive an exam-score curve from your own measurements.