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Ex 13.4
Ex 13.4, 2
Ex 13.4, 3 Important
Ex 13.4, 4 (i)
Ex 13.4, 4 (ii)
Ex 13.4, 4 (iii) Important
Ex 13.4, 5 (i) Important
Ex 13.4, 5 (ii)
Ex 13.4, 6 Important
Ex 13.4, 7 Important
Ex 13.4, 8
Ex 13.4, 9
Ex 13.4, 10
Ex 13.4, 11 Important
Ex 13.4, 12 Important
Ex 13.4, 13 Important Deleted for CBSE Board 2023 Exams
Ex 13.4, 14
Ex 13.4, 15 You are here
Ex 13.4, 16 (MCQ)
Ex 13.4, 17 (MCQ) Important
Last updated at March 16, 2023 by Teachoo
Ex 13.4, 15 In a meeting, 70% of the members favour and 30% oppose a certain proposal. A member is selected at random and we take X = 0 if he opposed, and X = 1 if he is in favour. Find E(X) and Var (X). Given that X = 0 is Members oppose X = 1 is members favour proposal Given, 70% of members favour proposal So, P(X = 1) = 70% = 0.7 and 30% of members oppose proposal So, P(X = 0) = 30% = 0.3 ∴ Probability distribution is The expectation value E(x) is given by : E 𝑿 = 𝑖 = 1𝑛𝑥𝑖𝑝𝑖 = 0 × 0.3 + 1 × 0.7 = 0.7 The variance of x is given by : Var 𝑋=𝐸 𝑋2− 𝐸 𝑋2 So, finding 𝐸 𝑋2 E 𝑿𝟐= 𝑖 = 1𝑛 𝑥𝑖2𝑝𝑖 = 02 × 0.3 + 12 × 0.7 = 0 + 0.7 = 0.7 Now, Var 𝒙 = 𝐸 𝑥2− 𝐸 𝑥2 = 0.7 – 0.72 = 0.7 1−0.7 = 0.7 0.3 = 0.21 Hence the expectation E(x) = 0.7 & variance var(x) = 0.21