A.For a group of individuals, the random variable x denotes the number of credit cards per individual with the following distribution. x: 0

Question

A.For a group of individuals, the random variable x denotes the number of credit cards per individual with the following distribution. x: 0 1 2 3 4 5 P(x): .27 .28 .20 .15 .08 .02 a. find the mean, variance and standard deviation of x b. find the probability that a randomly selected individual holds at least 1 card.

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Euphemia 4 years 2021-07-28T11:37:34+00:00 1 Answers 26 views 0

Answers ( )

  1. Delwyn
    0
    2021-07-28T11:39:30+00:00
    Reply

    Answer:

    1.55

    2.66

    1.631

    Step-by-step explanation:

    Given :

    x: 0 1 2 3 4 5

    P(x): .27 .28 .20 .15 .08 .02

    The expected mean, E(X) = Σ(x*p(x))

    E(X) = (0*0.27)+(1*0.28)+(2*0.20)+(3*0.15)+(4*0.08)+(5*0.02)

    E(X) = 1.55

    The expected variance :

    Σx²*p(x) – E(X)

    (0^2*0.27)+(1^2*0.28)+(2^2*0.20)+(3^2*0.15)+(4^2*0.08)+(5^2*0.02) – 1.55

    4.21 – 1.55 = 2.66

    The standard deviation :

    √variance = √2.66 = 1.631

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