Answer to Question #300588 in Statistics and Probability for Enzo

Question

Find the mean of the probability distribution of the random variable X which can take only values 2,4,5, and 9, given that P(2)=9/20, P(4)=1/20, P(5)=⅕, P(9)=3/10

Answer 1

For a probability distribution of a discrete random variable X, the mean is computed using the formula: 

μ_X  = Σ X_iP_i

Given

X 2 4 5 9

P(X) 9/20 1/20 1/5 3/10

Therefore, the mean;

μ_X  = Σ X_iP_i = 2(9/20) + 4(1/20) + 5(1/5) + 9(3/10) = 4.8