วิธีการคำนวณ Expected Value

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Expected Value (EV), also called mathematical expectation, is the probability-weighted average of all possible outcomes of a random variable. It represents the long-run average result if an experiment is repeated many times. EV is the cornerstone of decision theory, financial modelling, insurance, and gambling strategy.

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E

Σ xᵢ × P(xᵢ) for all outcomes i — Σ xᵢ × P(xᵢ) for all outcomes i

X

Σ xᵢ × P(xᵢ) for all outcomes i — Σ xᵢ × P(xᵢ) for all outcomes i

P

P value — Variable used in the calculation

คำแนะนำทีละขั้นตอน

1. 1E(X) = Σ xᵢ × P(xᵢ) for all outcomes i
2. 2All probabilities must sum to 1
3. 3Variance σ² = Σ P(xᵢ) × (xᵢ − E(X))²
4. 4Standard deviation σ = √Variance — measures spread around the mean
5. 5A positive EV game is profitable in the long run; negative EV is a loss

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