1. Quiz # 7 (A)1. Explain the concept of random variable with an example.2. The number of persons X, in a family chosen at random has the following probability distribution: X 1 2 3 4 5 6 P(X) 0 0.3 0.2 0 0.1 0.4 A) Find the average family size E(X). B) Also find V(X).3. f(x)=x5 ; 0<x<1 A) Find E(X). B) Also find V(X).4. Hospital records show that of patients suffering from a certain disease, 55% die of it. What is the probability that of 5 randomly selected patients, 3 will recover?5. A company makes electric motors. The probability an electric motor is defective is 0.01. What is the probability that a sample of 200 electric motors will contain exactly 4 defective motors?6. Find the following probabilities: (a) P(Z > 1.11) (b) (c) P(1.14 < Z < 2.05)
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