Question 6 - Mean or Expectation of random variable - Chapter 13 Class 12 Probability
Last updated at April 16, 2024 by Teachoo
Mean or Expectation of random variable
Mean or Expectation of random variable
Last updated at April 16, 2024 by Teachoo
Question 6 Let a pair of dice be thrown and the random variable X be the sum of the numbers that appear on the two dice. Find the mean or expectation of X. Since pair of die are thrown, Here, X = Sum of numbers on two die So, X can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 Thus, Probability distribution is Now, We need to find Mean or Expectation of X Mean or Expectation of X = = E(X) = = = 2 1 36 +3 2 36 +4 3 36 +5 4 36 +6 5 36 +7 6 36 +8 5 36 +9 4 36 +10 3 36 +11 2 36 +12 1 36 = 2 + 6 + 12 + 20 + 30 + 42 + 40 + 36 + 30 + 22 + 12 36 = 252 36 = 7 36 36 = 7 Thus mean or expectation is 7