A discrete random variable X takes values 10 , 20 , 30 and 40 , with probability 0 . 3 , 0 . 3 , 0 . 2 , 0 . 2 respectively. Then the expected value of X is

Step-by-step solution

Expected value of X is given by ∑ X P ( X ) , where P ( X ) is probability of random variable X . ⇒ ∑ X P ( X ) = 10 × 0 . 3 + 20 × 0 . 3 + 30 × 0 . 2 + 40 × 0 . 2 = 3 + 6 + 6 + 8 = 23