What you are given
- Values: 2, 3, 4, 5, 20
Formula: Q = gap / range; flag if Q > Q_crit
Statistics
How do you calculate dixon's Q outlier test?
Flag a suspect replicate (3 to 10 values). Advisory only, never auto-deleted. The relationship used is Q = gap / range; flag if Q > Q_crit.
Worked example
Every number below is computed by the calculator, not typed in
The working
- Q critical:
n=5, 95%=0.71 - Outliers flagged:
Q > Q_crit=20 (Q=0.833)
Flagged: 20 (Q > 0.71).
Do it with your own numbers.
The Dixon's Q outlier test calculator is free, shows every step, flags the hazards, and works offline once loaded. No account, no signup.
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