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Properties of Variance Calculator

Online variance properties: D(aX+b)=a²D(X); the constant b has no effect.

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D(aX+b)=a²D(X)
Coefficient
No effect

📖 Tutorial | Variance Properties

1. Definition
Variance properties: D(c)=0, D(aX+b)=a²D(X); for independent variables D(X+Y)=D(X)+D(Y).
2. Formula & Notation
a²Squared coefficient
3. Properties & Laws
  • Coefficient squared;
  • Constant has no effect;
  • D(c)=0;
  • Sums add only when independent.
4. Steps
  1. Enter the distribution and a,b;
  2. Click "Verify";
  3. Or click "Load Example".
5. Worked Examples
Example: D(X)=0.61,a=2: D(2X+3)=2.44.
6. Common Pitfalls
a²;
b has no effect;
Sums need independence.

❓ FAQ | Variance Properties

Coefficient?
Squared.
Constant?
No effect.
D(c)?
0.
Sum?
When independent.
Example?
2.44.
SD?
|a| times.