Question 6 - Mean or Expectation of random variable - Chapter 13 Class 12 Probability

Last updated at Dec. 16, 2024 by

Example 27 - Let random variable X be sum of numbers - Mean or Expectation of random variable

Example 27 - Chapter 13 Class 12 Probability - Part 2
Example 27 - Chapter 13 Class 12 Probability - Part 3
Example 27 - Chapter 13 Class 12 Probability - Part 4

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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

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo