MathematicsHigh School

Numerical characteristics of discrete random variables

Expectation and variance

Estimated time · 11 min 6 Content blocks

Core concepts

Formulas

E(X)=∑ixipiE(X) = \sum_i x_i p_i

Formulas

D(X)=∑i(xi−E(X))2piD(X) = \sum_i \bigl(x_i-E(X)\bigr)^2 p_i

Worked example

Worked example
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Prerequisites

Discrete random variables and their distributions10 min
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