Check sibling questions

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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Transcript

Example 27 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 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.