Discrete Random Variable Calculator: Mean, Variance & Standard Deviation

Calculate Discrete Random Variable Statistics

Enter comma-separated numerical values for X. Ensure there are no spaces between commas and numbers.
Enter comma-separated probabilities P(X) corresponding to each X value. These must be between 0 and 1, and their sum must equal 1.

Easily compute the mean (expected value), variance, and standard deviation for discrete probability distributions. Input your X values and their corresponding P(X) probabilities to instantly analyze your data. Essential for students, statisticians, and researchers needing quick statistical insights into random phenomena.

Formula:

E(X) = Σ [x · P(X=x)]
Var(X) = Σ [x2 · P(X=x)] - [E(X)]2
SD(X) = √Var(X)
Where x represents the random variable's value and P(X=x) is its corresponding probability.

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