ONE
    Númas
    ← Back to the programme
    NationalMediumProbability10–12

    A discrete random variable X takes the values 0, 1, 2 and 3 with probabilities 0.1, 0.3, 0.4 and 0.2. What is E(X)?

    Uma variável aleatória discreta X toma os valores 0, 1, 2 e 3 com probabilidades 0{,}1, 0{,}3, 0{,}4 e 0{,}2. Quanto é E(X)?

    Answer options

    Solution

    Step 1 of 3

    1. 1.The expectation weights each value by its probability: 0(0.1) + 1(0.3) + 2(0.4) + 3(0.2) = 0.3 + 0.8 + 0.6 = 1.7 = \frac{17}{10}.